Combined technology of SDS-CuO/TiO2 photocatalysis and sequencing batch reactor （SBR） were applied to treating dyestuff wastewater. Photocatalysis was carried out in a spiral up-flow type reactor as pre-treatment. S...Combined technology of SDS-CuO/TiO2 photocatalysis and sequencing batch reactor （SBR） were applied to treating dyestuff wastewater. Photocatalysis was carried out in a spiral up-flow type reactor as pre-treatment. SDS-CuO/TiO2 photocatalyst was prepared by modification of nano-TiO2 using CuO and sodium dodecyl sulfate （SDS）. Results show that the SDS-CuO/TiO2 photocatalyst contains two kinds of crystals, including TiO2 and CuO. The band gap of this photocatalyst is 1.56 eV, indicating that it can be excited by visible light （2〈794.87 nm）. And characterization also shows that there are alkyl groups on its surface. It takes 40 rain to improve the biodegradability of dyestuff wastewater. Five-day biochemical oxygen demand （BODs） and dehydrogenase activity （DHA） of wastewater reach the maximum value when dissolved oxygen is higher than 2.97 mg/L. SBR reactor was used to treat this biodegradability improved wastewater. Chemical oxygen demand （COD） and colority decline to 72 mg/L and 20 times, respectively, when the sludge loading is 0.179 kg（COD）/[kg（MLSS）＇d], dissolved oxygen is 4.09 mg/L and aeration time is 10 h.展开更多
Activated carbon/nanosized CdS/chitosan(AC/n-CdS/CS) composites as adsorbent and photoactive catalyst were prepared under low temperature(≤60 ℃) and ambient pressure.Methyl orange(MO) was chosen as a model pollutant...Activated carbon/nanosized CdS/chitosan(AC/n-CdS/CS) composites as adsorbent and photoactive catalyst were prepared under low temperature(≤60 ℃) and ambient pressure.Methyl orange(MO) was chosen as a model pollutant to evaluate synergistic effect of adsorption and photocatalytic decolorization by this innovative photocatalyst under visible light irradiation.Effects of various parameters such as catalyst amount,initial MO concentration,solution pH and reuse of catalyst on the decolorization of MO were investigated to optimize operational conditions.The decolorization of MO catalyzed by AC/n-CdS/CS fits the Langmuir-Hinshelwood kinetics model,and a surface reaction,where the dyes are absorbed,is the controlling step of the process.Decolorization efficiency of MO is improved with the increase in catalyst amount within a certain range.The photodecolorization of MO is more efficient in acidic media than alkaline media.The decolorization efficiency of MO is still higher than 84% after five cycles and 60 min under visible light irradiation,which confirms the reusability of AC/n-CdS/CS composite catalyst.展开更多
Transition metal dichalcogenides are interesting candidates as photocatalysts for hydrogen evolution reaction.The MnPSe_(3)/WS_(2) heterostructure is hence studied here with first principles calculations by exploring ...Transition metal dichalcogenides are interesting candidates as photocatalysts for hydrogen evolution reaction.The MnPSe_(3)/WS_(2) heterostructure is hence studied here with first principles calculations by exploring its electronic properties under the application of an electric field.It is discovered that the band gap will decrease from the WS_(2) monolayer to the MnPSe_(3)/WS_(2) heterostructure with Perdew-Burke-Ernzerhof functional,while increase slightly when electron correlation is involved.The conduction band minimum of the heterostructure is determined by the MnPSe3 layer,while the valence band maximum is contributed by the WS_(2)layer.The band edges and band gap suggest that the heterostructure will have good photocatalytic properties for water splitting.Moreover,comparing to monolayer WS_(2),the light absorption in both the ultraviolet and visible regions will be enhanced.When an electric field is present,a linear relation is observed between the electric field and the band gap within specific range,which can thus modulate the photocatalytic performance of this heterostructure.展开更多
AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(...AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.展开更多
A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform inf...A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform infrared(FIIR)spectra,scanning electron microscope(SEM),X-ray photoelectron spectra(XPS),and UV-Vis diffuse reflectance spectra(UV-Vis DRS).The SEM analyses indicate that the introduction of CS promotes the formation of a unique flower-like structure in BiOBr,which not only optimizes the efficiency of light capture but also increases the specific surface area of BiOBr.The bandgap of the composite was narrower compared with the pure BiOBr.The CS/BiOBr composites exhibited higher photocatalytic activity than pure CS and BiOBr under visible light irradiation,and a higher first-order reaction rate constant(k)of 0.0437 min-1 than BiOBr(0.0146 min^(-1)),and exhibited excellent stability and reusability during the cyclic run.The enhanced photocatalytic activity is attributed to the efficient separation of photoinduced electrons and holes.Superoxide radicals and holes were the major active species.展开更多
Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for ...Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties.Pulse electrolysis,a top-down electrochemical approach,has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides.This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte,obviating the need for additional capping agents in the synthesis process and eliminating the requirement for high-temperature post-treatments.The composition and microstructural characteristics of these oxides are found to be contingent upon the differing stabilities of tin fluoride and chloride complexes,as well as the distinct mechanisms of interaction between chloride and fluoride anions with an oxidized tin surface,which is influenced by the varying kosmotropic/chaotropic nature of these anions.The composition and microstructural characteristics of the obtained dispersed tin oxides would thus determine their potential applications as an anode material for lithium-ion batteries,as a photocatalyst,or as an oxyphilic component of a hybrid support for a platinum-containing electrocatalyst.展开更多
Photo-assisted Li-O2 batteries(LOBs)have remained a prominent and growing field over the past several years.However,the presence of slow oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),large charging ...Photo-assisted Li-O2 batteries(LOBs)have remained a prominent and growing field over the past several years.However,the presence of slow oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),large charging and discharging overpotentials,and unstable cycle life lead to low energy efficiency,thus limiting their commercial application.The rational design and synthesis of photocathode materials are effective ways to solve the above existing problems of photo-assisted LOB systems.Herein,the recent advances in the design and preparation of photocathode materials for photo-assisted LOBs were summarized in this review.First,we summarize the basic principles and comprehension of the reaction mechanism for photo-assisted LOBs.The second part introduces the latest research progress on photocathode materials.The third section describes the relationship between the structureproperties and electrochemistry of different photocathodes.In addition,attempts to construct efficient photocathode materials for photo-assisted LOBs through vacancy engineering,localized surface plasmon resonance(LSPR),and heterojunction engineering are mainly discussed.Finally,a discussion of attempts to construct efficient photocathode materials using other approaches is also presented.This work will motivate the preparation of stable and efficient photocathode materials for photo-assisted LOBs and aims to promote the commercial application of rechargeable photo-assisted LOBs energy storage.展开更多
The semiconductor photocatalysis are considered as one of the most promising candidates in hydrogen energy source and environmental remediation area.In this paper,flower-shaped SnS,is successfully combined on g-C,Ns,a...The semiconductor photocatalysis are considered as one of the most promising candidates in hydrogen energy source and environmental remediation area.In this paper,flower-shaped SnS,is successfully combined on g-C,Ns,and the well matching band structure successfully constitutes a new Type-II heterojunction.As expected,the photocatalytic hydrogen production experiment showed that the quantity of hydrogen produced on 5% SnS_(2)/C_(3)N_(5)was 922.5μmol/(g.h),which is 3.6 times higher than that of pure g-C_(3)N_(5).Meanwhile,in photocatalytic degradation of methylene blue,5%SnS2/C,Ns composite material can degrade 95% of contaminants within 40 min,showing good photocatalytic degradation performance.The mechanism study indicates that SnS_(2)/C_(3)N_(5)heterojunction improves the photogenerated charge migration rate and reduces the electron-hole recombination rate,and effectively improves the photocatalytic performance of g-C_(3)N_(5).This work provides a new idea for designing C,Ns-based heterojunctions with efficient hydrogen production and degradation performance.展开更多
In recent years,photocatalytic N_(2) reduction for ammonia synthesis at room temperature and atmospheric pressure has gradually become a research hotspot,exhibiting extremely high development potential.However,the low...In recent years,photocatalytic N_(2) reduction for ammonia synthesis at room temperature and atmospheric pressure has gradually become a research hotspot,exhibiting extremely high development potential.However,the low photogenerated charge separation efficiency and the lack of effective active sites seriously constrain the reaction efficiencies of semiconductor photocatalysts for N_(2) reduction of ammonia synthesis.Therefore,the rational design of catalytic materials is the key to enhance the photocatalytic N_(2) reduction reaction of ammonia synthesis.Transition metal Ru as the active center not only accelerates the adsorption and activation of N_(2) molecules,but also has good selectivity for N_(2) reduction.Moreover,the interaction between the metal and the support can effectively regulate the electronic structure of the active site,accelerate the photogenerated electron transfer,and significantly enhance the photocatalytic activity.Based on this,this review systematically investigates the Ru co-semiconductors to realize efficient photocatalytic N_(2) reduction for ammonia synthesis,and introduces its basic principles.Specifically,the Ru co-semiconductor photocatalytic material systems are introduced,such as TiO2-based,g-C3N4-based,and metal oxide materials,including the design of catalysts,crystal structures,and other characteristics.In addition,the modification strategies of photocatalytic N_(2) reduction ammonia synthesis materials are also presented,including loading/doping,defect engineering,construction of heterojunctions,and crystal surface modulation.Furthermore,the progress and shortcomings of the application of Ru co-semiconductors in these processes are summarized and comprehensively discussed,and the future outlook of Ru co-semiconductors in photocatalytic N_(2) reduction ammonia synthesis applications is proposed.展开更多
This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal me...This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.展开更多
A Co_(3)O_(4)/BiOBr heterojunction was synthesized via a facile one-step solvothermal method for highly selec-tive photocatalytic CO_(2)reduction.The optimized Co_(3)O_(4)/BiOBr-0.8 catalyst exhibited CO and CH_(4)evo...A Co_(3)O_(4)/BiOBr heterojunction was synthesized via a facile one-step solvothermal method for highly selec-tive photocatalytic CO_(2)reduction.The optimized Co_(3)O_(4)/BiOBr-0.8 catalyst exhibited CO and CH_(4)evolution rates of 112.2 and 5.5µmol·g^(-1)·h^(-1),respectively,representing 6.3-fold and 3.9-fold enhancements over pristine BiOBr.The heterojunction demonstrated broadened light absorption,enhanced photoelectrochemical activity,reduced charge-transfer resistance,and improved separation efficiency of photogenerated carriers(e^(-)/h^(+)).These synergistic effects were attributed to the formation of a Z-scheme heterostructure,which facilitated solar energy utilization and electron reduction capacity while suppressing carrier recombination.展开更多
Nitrogen doping has significant effects on the photocatalytic performance of ceria(CeO_(2)),and the possible synergistic effect with the inevitably introduced abundant oxygen vacancies(OVs)is of great significance for...Nitrogen doping has significant effects on the photocatalytic performance of ceria(CeO_(2)),and the possible synergistic effect with the inevitably introduced abundant oxygen vacancies(OVs)is of great significance for further investigation,and the specifically exposed crystal faces of CeO_(2)may have an impact on the performance of nitrogen doped CeO_(2).Herein,nitrogen-doped CeO_(2)with different morphologies and exposed crystal faces was prepared,and its performances in the photocatalytic degradation of tetracycline(TC)or hydrogen production via water splitting were evaluated.Density functional theory(DFT)was used to simulate the band structures,density of states,and oxygen defect properties of different CeO_(2)structures.It was found that nitrogen doping and OVs synergistically promoted the catalytic activity of nitrogen-doped CeO_(2).In addition,the exposed crystal faces of CeO_(2)have significant effects on the introduction of nitrogen and the ease of OV generation,as well as the synergistic effect of nitrogen doping with OVs.Among them,the rod-like nitrogen-doped CeO_(2)with exposed(110)face(R-CeO_(2)-NH_(3))showed a photocatalytic degradation ratio of 73.59%for TC and hydrogen production of 156.89μmol/g,outperforming other prepared photocatalysts.展开更多
With the gradual depletion of conventional fossil fuels,serious energy shortage has become a major societal challenge.Among the numerous new energy generation technologies,photocatalytic water splitting for hydrogen p...With the gradual depletion of conventional fossil fuels,serious energy shortage has become a major societal challenge.Among the numerous new energy generation technologies,photocatalytic water splitting for hydrogen production only requires abundant solar energy as the driving force and the process conditions are mild,green,and pollution-free.Thus,this technology has been proposed as an effective strategy to solve the current energy shortage crisis.The core of the photocatalytic hydrogen production technology is the photocatalyst.Therefore,it is necessary to develop efficient and stable photocatalysts.However,single-component photocatalysts usually exhibit insufficient photocatalytic H_(2)evolution efficiencies owing to its rapid hole-electron recombination,limited redox ability and low solar energy utilization efficiency.Therefore,various modification approaches have been designed to improve the photocatalytic H_(2)evolution efficiency of singlecomponent photocatalysts,such as element doping,cocatalyst modification,heterojunction construction,etc.Generally,element doping and cocatalyst modification improve the photocatalytic hydrogen production activity but cannot effectively solve the drawbacks of single-component photocatalysts,which limits their ability to improve the photocatalytic performance.However,constructing heterojunctions between two or more semiconductors simultaneously resolves these drawbacks.Compared with currently used conventional type-II all-solid-state Z-scheme,and liquid-phase Z-scheme heterojunctions,S-scheme heterojunctions present a more reasonable charge transfer mechanism,which is of great concern to and extensively used by several researchers.Therefore,this review firstly introduces the research background on S-scheme heterojunction photocatalytic systems,including the photocatalytic charge transfer mechanism of conventional type-II,all-solid-state Z-scheme,and liquid-phase Z-scheme heterojunction systems.Subsequently,the photocatalytic mechanism of S-scheme heterojunctions is meticulously explained.Additionally,the corresponding characterization methods,including in situ irradiated X-ray photoelectron spectroscopy(ISIXPS),Kelvin probe force microscopy(KPFM),selective deposition,electron paramagnetic resonance(EPR),density functional theory(DFT)calculations,etc.,are briefly summarized.Moreover,currently reported photocatalytic water splitting S-scheme heterojunctions and the corresponding significant enhancement in the hydrogen evolution mechanism are systematically summarized,including g-C_(3)N_(4)-,metal sulfide-,TiO_(2)-,other oxide-,and other S-scheme heterojunction-based photocatalysts.Notably,S-scheme heterojunction photocatalysts typically exhibit highly improved photocatalytic H_(2)evolution performance owing to their effective carrier separation and enhanced photoredox capacities.Finally,the bottlenecks of developing S-scheme heterojunctions for photocatalytic H_(2)production are presented,which require further investigation to enhance the photocatalytic efficiency of S-scheme heterojunctions for achieving industrial application standards.展开更多
The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for so...The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for solving environmental and energy issues.In 1972,TiO_(2) was applied for decomposing water into H_(2) and O_(2) via photocatalysis.Owing to its the low visible-light utilization,fast charge recombination,and high energy barrier for water oxidation,overall photocatalytic water-splitting efficiency is extremely low.Because H_(2) is more economically valuable than O_(2),sacrificial agent-assisted photocatalytic H_(2) evolution has been extensively investigated.Because the sacrificial agent can quickly consume photoexcited holes and effectively reduce the water oxidation energy barrier,photocatalytic H_(2) evolution efficiency can be increased by 3-4 orders of magnitude compared to photocatalytic water splitting.However,the overuse of sacrificial agents contributes to wasted photoexcited holes and expensive processes,while presenting potential environmental issues.Recently,overall charge utilization and improved redox efficiency have been achieved by coupling photocatalytic reduction with oxidation reactions.Moreover,overall charge utilization can boost charge separation and increase photocatalyst durability.However,the photocatalytic mechanism of the overall redox reactions remains unclear,owing to the complex reaction processes and design difficulties.Herein,the basic principles of photocatalysis are discussed from the perspective of light harvesting,photoexcited charge separation,thermodynamics,and redox reaction kinetics.Photocatalytic redox reactions,including overall water photodecomposition,photocatalytic H_(2) evolution coupled with organic oxidation,photocatalytic CO_(2) reduction coupled with organic oxidation,photocatalytic H_(2)O_(2) production coupled with organic oxidation,photocatalytic N_(2) reduction coupled with N_(2) oxidation,and photocatalytic organic reduction coupled with organic oxidation,can be systematically classified according to the coupling of photocatalytic oxidation reactions with photocatalytic reduction reactions.Subsequently,the design of photocatalytic redox reactions is considered in terms of the modulation of photocatalyst materials,reaction conditions,and diversity of reactants and products.In addition,the vital role of density functional theory(DFT)calculations for unveiling photoexcited charge transfer,rate-determining steps,and redox reaction barriers are discussed in the context of the work function,electron density difference,Bader charge,and variation in the intermediate adsorption free energy profiles.The activity and mechanism of various photocatalytic redox reactions were elaborately analyzed through in situ characterizations and DFT calculations using representative cases.Finally,the overall photocatalytic redox reactions were summarized with a focus on the construction of an S-scheme heterojunction photocatalyst,reasonable loading of cocatalysts,photocatalyst morphology regulation,novel photocatalyst development,reasonable selection of the oxidation half-reaction and reduction half-reaction for coupling,and combined in situ characterization and DFT calculations.This work provides a reference for promising design strategies and insight into the mechanism of overall photocatalytic redox reactions.展开更多
In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological charact...In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.展开更多
The hierarchical BiOX(X=Cl, Br, I) microflowers were successfully synthesized via simple precipitation method at 160 ℃ for 24 h and characterized by XRD, SEM, TEM, UV-vis DRS and N_2 adsorption-desorption techniques....The hierarchical BiOX(X=Cl, Br, I) microflowers were successfully synthesized via simple precipitation method at 160 ℃ for 24 h and characterized by XRD, SEM, TEM, UV-vis DRS and N_2 adsorption-desorption techniques. The as-prepared samples were pure phases and of microflowers composed of nanosheets which intercrossed with each other. The specific surface areas were about 22.9, 17.3 and 16.2 m^2/g for BiOCl, BiOBr and BiOI, respectively. The photocatalytic activities of BiOX powers were evaluated by RhB degradation under UV-vis light irradiation in the order of BiOCl > BiOBr > BiOI. Also, the kinetics of RhB degradation over BiOI was selectively investigated, demonstrating that the kinetics of Rh B degradation follows apparent first-order kinetics and fits the Langmuir-Hinshelwood model.展开更多
TiO2/Nb2O5 photocatalyst loaded with WO3 （WO3-TiO2/Nb2O5） was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse ...TiO2/Nb2O5 photocatalyst loaded with WO3 （WO3-TiO2/Nb2O5） was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy. The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiOjNb2O5 by using Fe^3＋ as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2% WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/（L·h）.展开更多
Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission ...Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-vis diffuse reflection spectroscopy and photoluminescence(PL) spectroscopy.The possible formation mechanism of Zn2GeO4 nanorods was discussed.It was supposed that the CTA+ cations preferentially adsorb on the planes of Zn2GeO4 nanorods,leading to preferential growth along the c-axis to form the Zn2GeO4 rods with larger aspect ratio and higher surface area,which showed the improved photocatalytic activity for photoreduction of CO2.The photoluminescence(PL) property of Zn2GeO4 nanorods was investigated through the emission spectra.展开更多
Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle...Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2'-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.展开更多
Visible-light-driven ZnGaNO solid solution–carbon nitride intercalation compound(CNIC) composite photocatalyst was synthesized via a mixing and heating method. The composite photocatalyst was characterized by X-ray d...Visible-light-driven ZnGaNO solid solution–carbon nitride intercalation compound(CNIC) composite photocatalyst was synthesized via a mixing and heating method. The composite photocatalyst was characterized by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), high-resolution transmission electron microscopy(HRTEM), Fourier transform infrared(FT-IR) spectroscopy, UV-vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy(XPS), photoluminescence(PL) spectroscopy and BET surface area measurements. The activity of ZnGaNO–CNIC composite photocatalyst for photodegradation of methyl orange(MO) is higher than that of either single-phase CNIC or ZnGaNO solid solution. The as-prepared composite photocatalysts exhibit an improved photocatalytic activity due to enhancement for the separation and transport of photo-generated electron–hole pairs.展开更多
基金Project(CDJZR11210009) supported by the Fundamental Research Funds for the Central Universities of China
文摘Combined technology of SDS-CuO/TiO2 photocatalysis and sequencing batch reactor （SBR） were applied to treating dyestuff wastewater. Photocatalysis was carried out in a spiral up-flow type reactor as pre-treatment. SDS-CuO/TiO2 photocatalyst was prepared by modification of nano-TiO2 using CuO and sodium dodecyl sulfate （SDS）. Results show that the SDS-CuO/TiO2 photocatalyst contains two kinds of crystals, including TiO2 and CuO. The band gap of this photocatalyst is 1.56 eV, indicating that it can be excited by visible light （2〈794.87 nm）. And characterization also shows that there are alkyl groups on its surface. It takes 40 rain to improve the biodegradability of dyestuff wastewater. Five-day biochemical oxygen demand （BODs） and dehydrogenase activity （DHA） of wastewater reach the maximum value when dissolved oxygen is higher than 2.97 mg/L. SBR reactor was used to treat this biodegradability improved wastewater. Chemical oxygen demand （COD） and colority decline to 72 mg/L and 20 times, respectively, when the sludge loading is 0.179 kg（COD）/[kg（MLSS）＇d], dissolved oxygen is 4.09 mg/L and aeration time is 10 h.
基金Project(21007044) supported by the National Natural Science Foundation of ChinaProject(20050532009) supported by the Doctoral Foundation of Ministry of Education of China
文摘Activated carbon/nanosized CdS/chitosan(AC/n-CdS/CS) composites as adsorbent and photoactive catalyst were prepared under low temperature(≤60 ℃) and ambient pressure.Methyl orange(MO) was chosen as a model pollutant to evaluate synergistic effect of adsorption and photocatalytic decolorization by this innovative photocatalyst under visible light irradiation.Effects of various parameters such as catalyst amount,initial MO concentration,solution pH and reuse of catalyst on the decolorization of MO were investigated to optimize operational conditions.The decolorization of MO catalyzed by AC/n-CdS/CS fits the Langmuir-Hinshelwood kinetics model,and a surface reaction,where the dyes are absorbed,is the controlling step of the process.Decolorization efficiency of MO is improved with the increase in catalyst amount within a certain range.The photodecolorization of MO is more efficient in acidic media than alkaline media.The decolorization efficiency of MO is still higher than 84% after five cycles and 60 min under visible light irradiation,which confirms the reusability of AC/n-CdS/CS composite catalyst.
基金Project(2682019CX06)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2019KY23)supported by Research Start-up Fund from the Southwest Jiaotong University,China+2 种基金Projects(20ZDYF0236,20ZDYF0490)supported by the Key R&D Projects in the Field of High and new Technology of Sichuan,ChinaProject(52072311)supported by the National Natural Science Foundation of ChinaProject(2019JDJQ0009)supported by the Outstanding Young Scientific and Technical Talents in Sichuan Province,China。
文摘Transition metal dichalcogenides are interesting candidates as photocatalysts for hydrogen evolution reaction.The MnPSe_(3)/WS_(2) heterostructure is hence studied here with first principles calculations by exploring its electronic properties under the application of an electric field.It is discovered that the band gap will decrease from the WS_(2) monolayer to the MnPSe_(3)/WS_(2) heterostructure with Perdew-Burke-Ernzerhof functional,while increase slightly when electron correlation is involved.The conduction band minimum of the heterostructure is determined by the MnPSe3 layer,while the valence band maximum is contributed by the WS_(2)layer.The band edges and band gap suggest that the heterostructure will have good photocatalytic properties for water splitting.Moreover,comparing to monolayer WS_(2),the light absorption in both the ultraviolet and visible regions will be enhanced.When an electric field is present,a linear relation is observed between the electric field and the band gap within specific range,which can thus modulate the photocatalytic performance of this heterostructure.
文摘AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.
文摘A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform infrared(FIIR)spectra,scanning electron microscope(SEM),X-ray photoelectron spectra(XPS),and UV-Vis diffuse reflectance spectra(UV-Vis DRS).The SEM analyses indicate that the introduction of CS promotes the formation of a unique flower-like structure in BiOBr,which not only optimizes the efficiency of light capture but also increases the specific surface area of BiOBr.The bandgap of the composite was narrower compared with the pure BiOBr.The CS/BiOBr composites exhibited higher photocatalytic activity than pure CS and BiOBr under visible light irradiation,and a higher first-order reaction rate constant(k)of 0.0437 min-1 than BiOBr(0.0146 min^(-1)),and exhibited excellent stability and reusability during the cyclic run.The enhanced photocatalytic activity is attributed to the efficient separation of photoinduced electrons and holes.Superoxide radicals and holes were the major active species.
基金supported by the Ministry of Science and Higher Education of the Russian Federation under Project FENN-2024-0002.
文摘Development of methodologies for fabrications of nanostructured materials that provide control over their microstructural features and compositions represents a fundamental step in the advancement of technologies for productions of materials with well-defined functional properties.Pulse electrolysis,a top-down electrochemical approach,has been demonstrated to be a viable method for producing nanostructured materials with a particular efficacy in the synthesis of tin oxides.This method allows for significant control over the composition and shape of the resulting tin oxides particles by modifying the anionic composition of the aqueous electrolyte,obviating the need for additional capping agents in the synthesis process and eliminating the requirement for high-temperature post-treatments.The composition and microstructural characteristics of these oxides are found to be contingent upon the differing stabilities of tin fluoride and chloride complexes,as well as the distinct mechanisms of interaction between chloride and fluoride anions with an oxidized tin surface,which is influenced by the varying kosmotropic/chaotropic nature of these anions.The composition and microstructural characteristics of the obtained dispersed tin oxides would thus determine their potential applications as an anode material for lithium-ion batteries,as a photocatalyst,or as an oxyphilic component of a hybrid support for a platinum-containing electrocatalyst.
文摘Photo-assisted Li-O2 batteries(LOBs)have remained a prominent and growing field over the past several years.However,the presence of slow oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),large charging and discharging overpotentials,and unstable cycle life lead to low energy efficiency,thus limiting their commercial application.The rational design and synthesis of photocathode materials are effective ways to solve the above existing problems of photo-assisted LOB systems.Herein,the recent advances in the design and preparation of photocathode materials for photo-assisted LOBs were summarized in this review.First,we summarize the basic principles and comprehension of the reaction mechanism for photo-assisted LOBs.The second part introduces the latest research progress on photocathode materials.The third section describes the relationship between the structureproperties and electrochemistry of different photocathodes.In addition,attempts to construct efficient photocathode materials for photo-assisted LOBs through vacancy engineering,localized surface plasmon resonance(LSPR),and heterojunction engineering are mainly discussed.Finally,a discussion of attempts to construct efficient photocathode materials using other approaches is also presented.This work will motivate the preparation of stable and efficient photocathode materials for photo-assisted LOBs and aims to promote the commercial application of rechargeable photo-assisted LOBs energy storage.
基金This project was supported by the Fundamental Research Program of Shanxi Province(202303021221058)。
文摘The semiconductor photocatalysis are considered as one of the most promising candidates in hydrogen energy source and environmental remediation area.In this paper,flower-shaped SnS,is successfully combined on g-C,Ns,and the well matching band structure successfully constitutes a new Type-II heterojunction.As expected,the photocatalytic hydrogen production experiment showed that the quantity of hydrogen produced on 5% SnS_(2)/C_(3)N_(5)was 922.5μmol/(g.h),which is 3.6 times higher than that of pure g-C_(3)N_(5).Meanwhile,in photocatalytic degradation of methylene blue,5%SnS2/C,Ns composite material can degrade 95% of contaminants within 40 min,showing good photocatalytic degradation performance.The mechanism study indicates that SnS_(2)/C_(3)N_(5)heterojunction improves the photogenerated charge migration rate and reduces the electron-hole recombination rate,and effectively improves the photocatalytic performance of g-C_(3)N_(5).This work provides a new idea for designing C,Ns-based heterojunctions with efficient hydrogen production and degradation performance.
基金supported by Taishan Scholars Foundation of Shandong province(tsqn 201909058)。
文摘In recent years,photocatalytic N_(2) reduction for ammonia synthesis at room temperature and atmospheric pressure has gradually become a research hotspot,exhibiting extremely high development potential.However,the low photogenerated charge separation efficiency and the lack of effective active sites seriously constrain the reaction efficiencies of semiconductor photocatalysts for N_(2) reduction of ammonia synthesis.Therefore,the rational design of catalytic materials is the key to enhance the photocatalytic N_(2) reduction reaction of ammonia synthesis.Transition metal Ru as the active center not only accelerates the adsorption and activation of N_(2) molecules,but also has good selectivity for N_(2) reduction.Moreover,the interaction between the metal and the support can effectively regulate the electronic structure of the active site,accelerate the photogenerated electron transfer,and significantly enhance the photocatalytic activity.Based on this,this review systematically investigates the Ru co-semiconductors to realize efficient photocatalytic N_(2) reduction for ammonia synthesis,and introduces its basic principles.Specifically,the Ru co-semiconductor photocatalytic material systems are introduced,such as TiO2-based,g-C3N4-based,and metal oxide materials,including the design of catalysts,crystal structures,and other characteristics.In addition,the modification strategies of photocatalytic N_(2) reduction ammonia synthesis materials are also presented,including loading/doping,defect engineering,construction of heterojunctions,and crystal surface modulation.Furthermore,the progress and shortcomings of the application of Ru co-semiconductors in these processes are summarized and comprehensively discussed,and the future outlook of Ru co-semiconductors in photocatalytic N_(2) reduction ammonia synthesis applications is proposed.
基金The project was supported by Natural Science Foundation of Shandong Province(ZR2021MB104)National Natural Science Foundation of China(22078174).
文摘This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.
文摘A Co_(3)O_(4)/BiOBr heterojunction was synthesized via a facile one-step solvothermal method for highly selec-tive photocatalytic CO_(2)reduction.The optimized Co_(3)O_(4)/BiOBr-0.8 catalyst exhibited CO and CH_(4)evolution rates of 112.2 and 5.5µmol·g^(-1)·h^(-1),respectively,representing 6.3-fold and 3.9-fold enhancements over pristine BiOBr.The heterojunction demonstrated broadened light absorption,enhanced photoelectrochemical activity,reduced charge-transfer resistance,and improved separation efficiency of photogenerated carriers(e^(-)/h^(+)).These synergistic effects were attributed to the formation of a Z-scheme heterostructure,which facilitated solar energy utilization and electron reduction capacity while suppressing carrier recombination.
基金Project(52164025)supported by the National Natural Science Foundation of ChinaProject([2020]1Y219)supported by the Basic Research Program from the Science&Technology Department of Guizhou Province,China+2 种基金Project([2019]30)supported by the Training Project from Guizhou University,ChinaProject([2023]04)supported by the Guizhou University Innovation Talent Team Project,ChinaProject([2022]041)supported by the Natural Science Research Project of Guizhou Provincial Department of Education,China。
文摘Nitrogen doping has significant effects on the photocatalytic performance of ceria(CeO_(2)),and the possible synergistic effect with the inevitably introduced abundant oxygen vacancies(OVs)is of great significance for further investigation,and the specifically exposed crystal faces of CeO_(2)may have an impact on the performance of nitrogen doped CeO_(2).Herein,nitrogen-doped CeO_(2)with different morphologies and exposed crystal faces was prepared,and its performances in the photocatalytic degradation of tetracycline(TC)or hydrogen production via water splitting were evaluated.Density functional theory(DFT)was used to simulate the band structures,density of states,and oxygen defect properties of different CeO_(2)structures.It was found that nitrogen doping and OVs synergistically promoted the catalytic activity of nitrogen-doped CeO_(2).In addition,the exposed crystal faces of CeO_(2)have significant effects on the introduction of nitrogen and the ease of OV generation,as well as the synergistic effect of nitrogen doping with OVs.Among them,the rod-like nitrogen-doped CeO_(2)with exposed(110)face(R-CeO_(2)-NH_(3))showed a photocatalytic degradation ratio of 73.59%for TC and hydrogen production of 156.89μmol/g,outperforming other prepared photocatalysts.
文摘With the gradual depletion of conventional fossil fuels,serious energy shortage has become a major societal challenge.Among the numerous new energy generation technologies,photocatalytic water splitting for hydrogen production only requires abundant solar energy as the driving force and the process conditions are mild,green,and pollution-free.Thus,this technology has been proposed as an effective strategy to solve the current energy shortage crisis.The core of the photocatalytic hydrogen production technology is the photocatalyst.Therefore,it is necessary to develop efficient and stable photocatalysts.However,single-component photocatalysts usually exhibit insufficient photocatalytic H_(2)evolution efficiencies owing to its rapid hole-electron recombination,limited redox ability and low solar energy utilization efficiency.Therefore,various modification approaches have been designed to improve the photocatalytic H_(2)evolution efficiency of singlecomponent photocatalysts,such as element doping,cocatalyst modification,heterojunction construction,etc.Generally,element doping and cocatalyst modification improve the photocatalytic hydrogen production activity but cannot effectively solve the drawbacks of single-component photocatalysts,which limits their ability to improve the photocatalytic performance.However,constructing heterojunctions between two or more semiconductors simultaneously resolves these drawbacks.Compared with currently used conventional type-II all-solid-state Z-scheme,and liquid-phase Z-scheme heterojunctions,S-scheme heterojunctions present a more reasonable charge transfer mechanism,which is of great concern to and extensively used by several researchers.Therefore,this review firstly introduces the research background on S-scheme heterojunction photocatalytic systems,including the photocatalytic charge transfer mechanism of conventional type-II,all-solid-state Z-scheme,and liquid-phase Z-scheme heterojunction systems.Subsequently,the photocatalytic mechanism of S-scheme heterojunctions is meticulously explained.Additionally,the corresponding characterization methods,including in situ irradiated X-ray photoelectron spectroscopy(ISIXPS),Kelvin probe force microscopy(KPFM),selective deposition,electron paramagnetic resonance(EPR),density functional theory(DFT)calculations,etc.,are briefly summarized.Moreover,currently reported photocatalytic water splitting S-scheme heterojunctions and the corresponding significant enhancement in the hydrogen evolution mechanism are systematically summarized,including g-C_(3)N_(4)-,metal sulfide-,TiO_(2)-,other oxide-,and other S-scheme heterojunction-based photocatalysts.Notably,S-scheme heterojunction photocatalysts typically exhibit highly improved photocatalytic H_(2)evolution performance owing to their effective carrier separation and enhanced photoredox capacities.Finally,the bottlenecks of developing S-scheme heterojunctions for photocatalytic H_(2)production are presented,which require further investigation to enhance the photocatalytic efficiency of S-scheme heterojunctions for achieving industrial application standards.
文摘The photoconversion of CO_(2) to carbon-containing fuels,splitting water into H_(2),selective organic synthesis,reduction of N_(2) to NH3,and hazardous organic contaminant degradation represent feasible schemes for solving environmental and energy issues.In 1972,TiO_(2) was applied for decomposing water into H_(2) and O_(2) via photocatalysis.Owing to its the low visible-light utilization,fast charge recombination,and high energy barrier for water oxidation,overall photocatalytic water-splitting efficiency is extremely low.Because H_(2) is more economically valuable than O_(2),sacrificial agent-assisted photocatalytic H_(2) evolution has been extensively investigated.Because the sacrificial agent can quickly consume photoexcited holes and effectively reduce the water oxidation energy barrier,photocatalytic H_(2) evolution efficiency can be increased by 3-4 orders of magnitude compared to photocatalytic water splitting.However,the overuse of sacrificial agents contributes to wasted photoexcited holes and expensive processes,while presenting potential environmental issues.Recently,overall charge utilization and improved redox efficiency have been achieved by coupling photocatalytic reduction with oxidation reactions.Moreover,overall charge utilization can boost charge separation and increase photocatalyst durability.However,the photocatalytic mechanism of the overall redox reactions remains unclear,owing to the complex reaction processes and design difficulties.Herein,the basic principles of photocatalysis are discussed from the perspective of light harvesting,photoexcited charge separation,thermodynamics,and redox reaction kinetics.Photocatalytic redox reactions,including overall water photodecomposition,photocatalytic H_(2) evolution coupled with organic oxidation,photocatalytic CO_(2) reduction coupled with organic oxidation,photocatalytic H_(2)O_(2) production coupled with organic oxidation,photocatalytic N_(2) reduction coupled with N_(2) oxidation,and photocatalytic organic reduction coupled with organic oxidation,can be systematically classified according to the coupling of photocatalytic oxidation reactions with photocatalytic reduction reactions.Subsequently,the design of photocatalytic redox reactions is considered in terms of the modulation of photocatalyst materials,reaction conditions,and diversity of reactants and products.In addition,the vital role of density functional theory(DFT)calculations for unveiling photoexcited charge transfer,rate-determining steps,and redox reaction barriers are discussed in the context of the work function,electron density difference,Bader charge,and variation in the intermediate adsorption free energy profiles.The activity and mechanism of various photocatalytic redox reactions were elaborately analyzed through in situ characterizations and DFT calculations using representative cases.Finally,the overall photocatalytic redox reactions were summarized with a focus on the construction of an S-scheme heterojunction photocatalyst,reasonable loading of cocatalysts,photocatalyst morphology regulation,novel photocatalyst development,reasonable selection of the oxidation half-reaction and reduction half-reaction for coupling,and combined in situ characterization and DFT calculations.This work provides a reference for promising design strategies and insight into the mechanism of overall photocatalytic redox reactions.
文摘In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.
基金Project(21301194)supported by the National Natural Science Foundation of ChinaProject(20130162120031)supported by Research Fund for the Doctoral Program of Higher Education of China
文摘The hierarchical BiOX(X=Cl, Br, I) microflowers were successfully synthesized via simple precipitation method at 160 ℃ for 24 h and characterized by XRD, SEM, TEM, UV-vis DRS and N_2 adsorption-desorption techniques. The as-prepared samples were pure phases and of microflowers composed of nanosheets which intercrossed with each other. The specific surface areas were about 22.9, 17.3 and 16.2 m^2/g for BiOCl, BiOBr and BiOI, respectively. The photocatalytic activities of BiOX powers were evaluated by RhB degradation under UV-vis light irradiation in the order of BiOCl > BiOBr > BiOI. Also, the kinetics of RhB degradation over BiOI was selectively investigated, demonstrating that the kinetics of Rh B degradation follows apparent first-order kinetics and fits the Langmuir-Hinshelwood model.
基金Project(2002AA327140) supported by National High-Tech Research and Development Program of China
文摘TiO2/Nb2O5 photocatalyst loaded with WO3 （WO3-TiO2/Nb2O5） was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy. The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiOjNb2O5 by using Fe^3＋ as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2% WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/（L·h）.
基金Project(51208102)supported by the National Natural Science Foundation of China
文摘Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-vis diffuse reflection spectroscopy and photoluminescence(PL) spectroscopy.The possible formation mechanism of Zn2GeO4 nanorods was discussed.It was supposed that the CTA+ cations preferentially adsorb on the planes of Zn2GeO4 nanorods,leading to preferential growth along the c-axis to form the Zn2GeO4 rods with larger aspect ratio and higher surface area,which showed the improved photocatalytic activity for photoreduction of CO2.The photoluminescence(PL) property of Zn2GeO4 nanorods was investigated through the emission spectra.
基金Projects(07/RFP/MASF386,201109019) supported by the Science Foundation Ireland and Ministry of Environmental Protection under the Research Frontiers Program,Ireland
文摘Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2'-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.
基金Project(51208102)supported by the National Natural Science Foundation of China
文摘Visible-light-driven ZnGaNO solid solution–carbon nitride intercalation compound(CNIC) composite photocatalyst was synthesized via a mixing and heating method. The composite photocatalyst was characterized by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), high-resolution transmission electron microscopy(HRTEM), Fourier transform infrared(FT-IR) spectroscopy, UV-vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy(XPS), photoluminescence(PL) spectroscopy and BET surface area measurements. The activity of ZnGaNO–CNIC composite photocatalyst for photodegradation of methyl orange(MO) is higher than that of either single-phase CNIC or ZnGaNO solid solution. The as-prepared composite photocatalysts exhibit an improved photocatalytic activity due to enhancement for the separation and transport of photo-generated electron–hole pairs.
