Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditi...Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditions(160℃)in a NaOH–H2O system with ammelide and ammeline as the main degradation products.The alkaline solvent had an obvious corrosion effect for MFF,as indicated by scanning electron microscopy(SEM).The reaction process and products distribution were studied by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and ^(13)C nuclear magnetic resonance(NMR).Besides,the MFF degradation products that have the similar chemical structures and bonding performances to those of melamine can be directly used as the raw material for synthesis of melamine urea-formaldehyde resins(MUFs).Moreover,the degradation system demonstrated here showed the high degradation efficiency after reusing for 7 times.The degradation process generated few harmful pollutants and no pre-or post-treatments were required,which proves its feasibility in the safe removal or recovery of waste MFF.展开更多
Unsatisfactory conductivity and volume effects have hindered the commercial application of siliconbased materials as advanced anode materials for high-performance lithium-ion batteries. Herein, nitrogen doped carbon s...Unsatisfactory conductivity and volume effects have hindered the commercial application of siliconbased materials as advanced anode materials for high-performance lithium-ion batteries. Herein, nitrogen doped carbon silicon matrix composite with atomically dispersed Co sites(Si/Co-N-C) is obtained via the design of the frame structure loaded with nano-components and the multi-element hybrid strategy. Co atoms are uniformly fixed to the N-C frame and tightly packed with nanoscale silicon particles as an activation and protection building block. The mechanism of the N-C framework of loaded metal Co in the Si alloying process is revealed by electrochemical kinetic analysis and ex situ characterization tests.Impressively, the nitrogen-doped Co site activates the intercalation of the outer carbon matrix to supplement the additional capacity. The Co nanoparticles with high conductivity and support enhance the conductivity and structural stability of the composite, accelerating the Li^(+)/Na^(+) diffusion kinetics. Density functional theory(DFT) calculation confirms that the hetero-structure Si/Co-N-C adjusts the electronic structure to obtain good lithium-ion adsorption energy, reduces the Li^(+)/Na^(+) migration energy barrier.This work provides meaningful guidance for the development of high-performance metal/non-metal modified anode materials.展开更多
It is very appealing that 5-hydroxymethylfurfural(HMF)is electrocatalytical oxidized as 2,5-furandicarboxylic acid(FDCA)linking to non-classical cathodic hydrogen(H_(2))production.However,the electrocatalysts for elec...It is very appealing that 5-hydroxymethylfurfural(HMF)is electrocatalytical oxidized as 2,5-furandicarboxylic acid(FDCA)linking to non-classical cathodic hydrogen(H_(2))production.However,the electrocatalysts for electrocatalytic HMF oxidative reaction(e-HMFOR)have been facing low Faradaic efficiency(FE)and high water splitting voltage.Herein,we propose a strategy of the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction by constructing a Co-Ni paired site,where the Co site is in charge of adsorbing for HMF while the electrons are transferred to the Ni site,thus giving the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction superior electrocata lytic performances for e-HMFOR and water splitting.By optimizing conditions,the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction has high conversion of 99.7%,high selectivity of 99.9%,and high FE of 98.4%at 1.3 V,as well as low cell voltage of 1.31 V at 10 mA cm^(-2)in 1 M KOH+0.1 M HMF.This study offers a potential insight for e-HMFOR to high value-added FDCA coupling water splitting to produce H_(2)in an economical manner.展开更多
The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH...The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH_4 are considered as promising candidates for the replacement of traditional fossil fuels. However, the technologies for the storage of these gases are still immature. In addition, the release of anthropogenic toxic gases into the atmosphere is a worldwide threat of growing concern. Both in academia and industry, considerable research efforts have been devoted to developing advanced porous materials for the effective and energy-efficient separation, storage, or capture of the related gases. In contrast to conventional inorganic porous materials such as zeolites and activated carbons, metal–organic frameworks(MOFs) are considered as a type of promising materials for gas separation and storage. In this contribution, we review the recent research advance of MOFs in some relevant applications, including CO_2 capture, O_2 purification, separation of light hydrocarbons, separation of noble gases, storage of gases(CH_4,H_2, and C_2 H_2) for energy, and removal of some gaseous air pollutants(NH_3, NO_2, and SO_2). Finally, an outlook regarding the challenges of the future research of MOFs in these directions is given.展开更多
Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave h...Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were investigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were analyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.展开更多
Perovskite-like oxide La2-xSrxCuO4 （x = 0, 1） single crystallites with microrod-like morphologies and tetragonal crystal structures were prepared hydrothermally at 240 ℃ with poly（ethylene glycol） （PEG） or hexa...Perovskite-like oxide La2-xSrxCuO4 （x = 0, 1） single crystallites with microrod-like morphologies and tetragonal crystal structures were prepared hydrothermally at 240 ℃ with poly（ethylene glycol） （PEG） or hexadecyltrimethyl ammonium bromide （CTAB） as a surfactant and after calcination at 850 ℃. The physicochemical properties of the materials were characterized by means of XRD, BET, SEM, TEM/SAED （selected-area electron diffraction）, XPS and H2-TPR techniques. It is found that doping Sr2＋ to La2CuO4 lattice enhanced the catalytic activity for methane combustion and the LaSrCuO4 catalyst derived from PEG is the best among the tested ones. It is concluded that factors, such as adsorbed oxygen species concentration, reducibility and surface area, determined the catalytic performance of such single-crystalline materials.展开更多
A thermogravimetric analysis (TG) was conducted to study the thermal decomposition behavior and kinetics of composites from coal and high density polyethylene (HDPE), linear low density polyethylene (LLDPE) or low den...A thermogravimetric analysis (TG) was conducted to study the thermal decomposition behavior and kinetics of composites from coal and high density polyethylene (HDPE), linear low density polyethylene (LLDPE) or low density polyethylene (LDPE). The results show that coal facilitates melting of the polyethylene before temperatures reach 700 K in nitrogen due to the exothermic effect of coal. Above 700 K, adding coal into the polyethylene will result in smaller maximum rates of mass loss and higher initial mass loss temperatures of the composites. Hence, some chemical interactions, occurring between liquid compounds released in the pyrolysis of the coal and polymer, depend on several factors, such as coal rank and the molecular structure of polymers. Synergetic effects in coal and polymers were also found. Both chemical interactions and synergetic effects control the entire thermal decomposition behavior of compos- ites. The larger the amount of coal in the composites, the greater the decomposition temperature spans and the higher the maximum decomposition temperature, the smaller the devolatilization rates. The effect of coal on the thermal stability of composites lies in the hydrogen acceptor effect of the coals. Thermal decomposition of the coals, the polymers and related composites can be modelled via first order parallel reactions between 563 K and 763 K.展开更多
The abundance of low-rank coals in China, such as bituminous and brown coals, makes studies of their composition and structure of great significance to both coal chemistry research and for efficient utilization of the...The abundance of low-rank coals in China, such as bituminous and brown coals, makes studies of their composition and structure of great significance to both coal chemistry research and for efficient utilization of the coal. We describe how a Chinese brown coal was ultrasonically extracted with carbon disulfide （CS2） and the raw and extracted coals were characterized by Fourier Transform Infrared Spectroscopy （FTIR）. The corresponding extract was analyzed with a coupled gas chromatograph mass spectrometer （GC/MS）. The FTIR analysis shows a great abundance of amidocyanogen, carbonyl, aromatic and hetero aromatic rings and single carbon-beteroatom bonds. This suggests the possible occurrence of compounds like alcohols, phenols, amines, esters, carboxylic acids, ethers, aromatics or heteroaromatics. The GC/MS analysis of the CS2 extract detected 62 compounds, among which the non-polar ones were of lower abundance while the polar ones were in higher abundance and were structurally diverse. This demonstrates the compositional and structural complexity of Shengli coal.展开更多
In situ chemical oxidation polymerization of pyrrole on the surface of sulfur particles was carried out to synthesize a sulfur/polypyrrole （SIPPy） nanocomposite with core-shell structure. The composite was character...In situ chemical oxidation polymerization of pyrrole on the surface of sulfur particles was carried out to synthesize a sulfur/polypyrrole （SIPPy） nanocomposite with core-shell structure. The composite was characterized by elemental analysis, X-ray diffraction, scanning/transmission electron microscopy, and electrochemical measurements. XRD and FTIR results showed that sulfur well dispersed in the core-shell structure and PPy structure was successfully obtained via in situ oxidative polymerization of pyrrole on the surface of sulfur particles. TEM observation revealed that PPy was formed and fixed to the surface of sulfur nanoparticle after polymerization, developing a well-defined core-shell structure and the thickness of PPy coating layer was in the range of 20-30 nm. In the composite, PPy worked as a conducting matrix as well as a coating agent, which confined the active materials within the electrode. Consequently, the as prepared SIPPy composite cathode exhibited good cycling and rate performances for rechargeable lithium/sulfur batteries. The resulting cell containing SIPPy composite cathode yields a discharge capacity of 1039 mAh·g^-1 at the initial cycle and retains 59% of this value over 50 cycles at 0.1 C rate. At 1 C rate, the SIPPy composite showed good cycle stability, and the discharge capacity was 475 mAh·g^-1 after 50 cycles.展开更多
This paper has provided an effective method to utilize the flter residue. A Y zeolite-containing composite and a fuid catalytic cracking （FCC） catalyst had been successfully prepared by an in-situ crystallization te...This paper has provided an effective method to utilize the flter residue. A Y zeolite-containing composite and a fuid catalytic cracking （FCC） catalyst had been successfully prepared by an in-situ crystallization technology using flter residue and kaolin as raw materials. The samples were characterized by XRD, FT-IR, SEM, and N2 adsorption-desorption techniques and evaluated in a bench FCC unit. In comparison to the reference samples synthesized from single kaolin, the silica/alumina molar ratio, the external surface area, and the total pore volume of the composite increased by 16.2%, 14.5%, and 16.2%, respectively. The catalyst possessed more meso- and macro-pores and more acid sites than the reference catalyst, and exhibited better coke selectivity. The prepared catalyst had the optimum isomerization and aromatization performance. The olefn content in the cracked gasoline obtained over this catalyst was reduced by 5.05 percentage points with the research octane number of gasoline increased by 0.5 units.展开更多
All-polymer solar cells(all-PSCs)possess attractive merits including superior thermal stability and mechanical flexibility for large-area roll-to-roll processing.Introducing flexible conjugation-break spacers(FCBSs)in...All-polymer solar cells(all-PSCs)possess attractive merits including superior thermal stability and mechanical flexibility for large-area roll-to-roll processing.Introducing flexible conjugation-break spacers(FCBSs)into backbones of polymer donor(P_(D))or polymer acceptor(P_(A))has been demonstrated as an efficient approach to enhance both the photovoltaic(PV)and mechanical properties of the all-PSCs.However,length dependency of FCBS on certain all-PSC related properties has not been systematically explored.In this regard,we report a series of new non-conjugated P_(A)s by incorporating FCBS with various lengths(2,4,and 8 carbon atoms in thioalkyl segments).Unlike com-mon studies on so-called side-chain engineering,where longer side chains would lead to better solubility of those resulting polymers,in this work,we observe that the solubilities and the resulting photovoltaic/mechanical properties are optimized by a proper FCBS length(i.e.,C2)in P_(A) named PYTS-C2.Its all-PSC achieves a high efficiency of 11.37%,and excellent mechanical robustness with a crack onset strain of 12.39%,significantly superior to those of the other P_(A)s.These results firstly demonstrate the effects of FCBS lengths on the PV performance and mechanical properties of the all-PSCs,providing an effective strategy to fine-tune the structures of P_(A)s for highly efficient and mechanically robust PSCs.展开更多
A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on des...A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.展开更多
Herein,a facile synthetic strategy is proposed to fabricate high-performance electrocatalysts for rechargeable Zn-air batteries(ZABs).Heterostructured NiCo/NiCo_(2)S_(4) nanoparticles encapsulated in N-,S-co-doped CNT...Herein,a facile synthetic strategy is proposed to fabricate high-performance electrocatalysts for rechargeable Zn-air batteries(ZABs).Heterostructured NiCo/NiCo_(2)S_(4) nanoparticles encapsulated in N-,S-co-doped CNT(NiCo/NiCo_(2)S_(4)@NSCNT) are synthesized via co-precipitation,thermal carbonization,and partial sulfidation processes.The strongly coupled NiCo/NiCo_(2)S_(4) heterostructure can improve the redox property and charge transfer ability.Also,the CNTs with abundant foreign dopants provide high electrical conductivity and abundant defect sites for both the oxygen evolution reaction(OER) and oxygen reduction reaction(ORR).The prepared NiCo/NiCo_(2)S_(4)@NSCNT electrocatalyst exhibits a low overpotential of 349 mV at a current density of 10 mA cm-2 and a half-wave potential of 0.865 V for the OER and ORR,respectively.Moreover,the ZAB assembled using as-prepared NiCo/NiCo_(2)S_(4)@NSCNT can provide superior specific capacity(756.16 mA h g_(Zn)^(-1)],peak power density(155.82 mW cm^(-2)),and long-term cyclability compared to those of the precious metal-based electrocatalyst(Pt/C+RuO_(2)).展开更多
Formic acid photodegradation is one of the most important reactions in organic pollution control, and helps to improve the hydrogen generation efficiency in titanium dioxide catalyzed water photodecomposition. Based o...Formic acid photodegradation is one of the most important reactions in organic pollution control, and helps to improve the hydrogen generation efficiency in titanium dioxide catalyzed water photodecomposition. Based on density functional theory and Reax FF molecular dynamics, the adsorption, diffusion and activation of formic acid on the different anatase TiO（101）,（001）,（010） surfaces are investigated.The result shows that the adsorption of COOH on anatase TiOsurface shrinks the energy gap between the dehydrogenation intermediate COOH and HCOO. On the anatase TiO（101） surface, the formic acid breaks the O–H bond at the first step with activation energy 0.24 eV, and the consequent break of α-H become much easier with activation energy 0.77 eV. The dissociation of α-H is the determination step of the HCOOH decomposition.展开更多
In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system o...In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.展开更多
Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56....Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.7% of zeolite Y and exhibited a much larger specific surface area and pore volume as well as strong hydrothermal stability. Fluid catalytic cracking(FCC) catalyst was prepared based on the composite material. The results indicated that the as-prepared catalyst possessed a unique pore structure that was advantageous to the diffusion-controlled reactions. In addition, the attrition resistance, activity and hydrothermal stability of the studied catalyst were superior to those of the reference catalyst. The catalyst also exhibited excellent nickel and vanadium passivation performance, strong bottoms upgrading selectivity, and better gasoline and coke selectivity. In comparison to the reference catalyst, the yields of the gasoline and light oil increased by 1.61 and 1.31 percentage points, respectively, and the coke yield decreased by 0.22 percentage points, and the olefin content in the produced gasoline reduced by 2.51 percentage points, with the research octane number increased by 0.7 unit.展开更多
Production of ceramic armour solutions on-demand/in-theatre would have significant logistical and military advantages.However,even assuming that such technologies could be successfully deployed in the field,such near ...Production of ceramic armour solutions on-demand/in-theatre would have significant logistical and military advantages.However,even assuming that such technologies could be successfully deployed in the field,such near net-shape manufacturing technology is relatively immature compared to conventional sintering of ceramics.In this study,the ballistic performance of a series of additively manufactured(AM)/rapidly-prototyped(RP)alumina tiles of 97.2%of the density of Sintox FATM were investigated using both forward-and reverse-ballistic experiments.These experiments,undertaken with compressed gasguns,employed the depth-of-penetration technique and flash X-ray as primary diagnostics to interrogate both efficiency of penetration and projectile-target interaction,respectively.The RP alumina was found to exhibit useful ballistic properties,successfully defeating steel-cored(AP)7.62×39 mm BXN rounds at velocities of up-to c.a.850 m/s,while exhibiting comparable failure modes to conventionally sintered armour-grade Sintox FATM.However,where a<1%by vol.Cu dopant was introduced into the RP material failure modes changed dramatically with performance dropping below that of conventionally sintered alumina.Overall,the results from both sets of experiments were complimentary and clearly indicated the potential of such RP materials to play an active role in provision of real-world body armour solutions provided quality control of the RP material can be maintained.展开更多
The effect of annealing on the microstructure and electrical characteristics of poly （3-hexylthiophene） （P3HT） films doped with very small amounts of the electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoqui...The effect of annealing on the microstructure and electrical characteristics of poly （3-hexylthiophene） （P3HT） films doped with very small amounts of the electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane （F4-TCNQ） is studied. X-ray diffraction and UV-vis spectrum studies show that unlike the pure P3HT film, the thermal treatment on the doped fihns under an Ar atmosphere can effectively enhance the crystalline order of P3HT films, as well as successfully facilitate the orientation of the polymer chains. This improvement is attributed to the electrostatic force between P3HT and F4-TCNQ molecules. This force induces the polymer chains to crystallize and orient during the annealing process. As a result, annealing significantly improves performance, especially for the Ion/Ioff ratio of the TFTs based on the doped P3HT films.展开更多
Effects of dopant properties on microstructures and the electrical characteristics of poly （3-hexylthiophene） （P3HT） films are studied by doping 0.1 wt% 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane （F4？T...Effects of dopant properties on microstructures and the electrical characteristics of poly （3-hexylthiophene） （P3HT） films are studied by doping 0.1 wt% 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane （F4？TCNQ）, 6,6-phenyl-C61butyric acid methyl ester （PCBM） and N,N＇？Diphenyl-N,N＇-（m-tolyl）-benzidine （TPD） into P3HT, respectively. The introductions of various dopants in small quantities increase the field-effect mobility and the I on/Ioff ratio of P3HT thin-film transistors. However, each of dopants shows various effects on the crystalline order and the molecular orientation of P3HT films and the performance of P3HT thin-film transistors. These can be attributed to the various size, shape and energy-level properties of the dopants.展开更多
Herein,incremental capacity-differential voltage (IC-DV) at a high C-rate (HC) is used as a non-invasive diagnostic tool in lithium-ion batteries,which inevitably exhibit capacity fading caused by multiple mechanisms ...Herein,incremental capacity-differential voltage (IC-DV) at a high C-rate (HC) is used as a non-invasive diagnostic tool in lithium-ion batteries,which inevitably exhibit capacity fading caused by multiple mechanisms during charge/discharge cycling.Because battery degradation modes are complex,the simple output of capacity fading does not yield any useful data in that respect.Although IC and DV curves obtained under restricted conditions (<0.1C,25℃) were applied in non-invasive analysis for accurate observation of degradation symptoms,a facile,rapid diagnostic approach without intricate,complex calculations is critical in on-board applications.Herein,Li Ni_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC532)/graphite pouch cells were cycled at 4 and 6C and the degradation characteristics,i.e.,loss of active materials (LAM) and loss of lithium inventory (LLI),were parameterized using the IC-DV curves.During the incremental current cycling,the initial steep LAM and LLI slopes underwent gradual transitions to gentle states and revealed the gap between low-and high-current measurements.A quantitative comparison of LAM at high and low C-rate showed that a IC;revealed the relative amount of available reaction region limited by cell polarization.However,this did not provide a direct relationship for estimating the LAM at a low C-rate.Conversely,the limiting LLI,which is calculated at a C-rate approaching 0,was obtained by extrapolating the LLI through more than two points measured at high C-rate,and therefore,the LLI at 0.1C was accurately determined using rapid cycling.展开更多
基金supported by the National Natural Science Foundation of China(No.21774139)China,Key Research and Development Program of Shanxi Province,China(No,202102040201009)special fund of Beijing Key Laboratory of Clean Fuels and Efficient Catalytic Emission Reduction Technology and the Fund for Shanxi“1331 Project”.Thanks to Ningbo Kejiang Culture Sci.&Tech.Development Co.,Ltd.for the help in schematic drawing。
文摘Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin wastes.Herein,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditions(160℃)in a NaOH–H2O system with ammelide and ammeline as the main degradation products.The alkaline solvent had an obvious corrosion effect for MFF,as indicated by scanning electron microscopy(SEM).The reaction process and products distribution were studied by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and ^(13)C nuclear magnetic resonance(NMR).Besides,the MFF degradation products that have the similar chemical structures and bonding performances to those of melamine can be directly used as the raw material for synthesis of melamine urea-formaldehyde resins(MUFs).Moreover,the degradation system demonstrated here showed the high degradation efficiency after reusing for 7 times.The degradation process generated few harmful pollutants and no pre-or post-treatments were required,which proves its feasibility in the safe removal or recovery of waste MFF.
基金Research and Development Plan Project in Key Fields of Guangdong Province (2020B0101030005)Basic and Applied Basic Research Fund of Guangdong Province (2019B1515120027)+1 种基金Scientific Research Innovation Project of Graduate School of South China Normal University (2024KYLX050)Special Funds for the Cultivation of Guangdong College Students’ Scientific and Technological Innovation (“Climbing Program” Special Funds, pdjh2024a109)。
文摘Unsatisfactory conductivity and volume effects have hindered the commercial application of siliconbased materials as advanced anode materials for high-performance lithium-ion batteries. Herein, nitrogen doped carbon silicon matrix composite with atomically dispersed Co sites(Si/Co-N-C) is obtained via the design of the frame structure loaded with nano-components and the multi-element hybrid strategy. Co atoms are uniformly fixed to the N-C frame and tightly packed with nanoscale silicon particles as an activation and protection building block. The mechanism of the N-C framework of loaded metal Co in the Si alloying process is revealed by electrochemical kinetic analysis and ex situ characterization tests.Impressively, the nitrogen-doped Co site activates the intercalation of the outer carbon matrix to supplement the additional capacity. The Co nanoparticles with high conductivity and support enhance the conductivity and structural stability of the composite, accelerating the Li^(+)/Na^(+) diffusion kinetics. Density functional theory(DFT) calculation confirms that the hetero-structure Si/Co-N-C adjusts the electronic structure to obtain good lithium-ion adsorption energy, reduces the Li^(+)/Na^(+) migration energy barrier.This work provides meaningful guidance for the development of high-performance metal/non-metal modified anode materials.
基金supported by the National Natural Science Foundation of China(22302019)the Changzhou Sci&Tech Program(CJ20220214).
文摘It is very appealing that 5-hydroxymethylfurfural(HMF)is electrocatalytical oxidized as 2,5-furandicarboxylic acid(FDCA)linking to non-classical cathodic hydrogen(H_(2))production.However,the electrocatalysts for electrocatalytic HMF oxidative reaction(e-HMFOR)have been facing low Faradaic efficiency(FE)and high water splitting voltage.Herein,we propose a strategy of the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction by constructing a Co-Ni paired site,where the Co site is in charge of adsorbing for HMF while the electrons are transferred to the Ni site,thus giving the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction superior electrocata lytic performances for e-HMFOR and water splitting.By optimizing conditions,the NiSeO_(3)@(CoSeO_(3))_(4)heterojunction has high conversion of 99.7%,high selectivity of 99.9%,and high FE of 98.4%at 1.3 V,as well as low cell voltage of 1.31 V at 10 mA cm^(-2)in 1 M KOH+0.1 M HMF.This study offers a potential insight for e-HMFOR to high value-added FDCA coupling water splitting to produce H_(2)in an economical manner.
基金supported from the Natural Science Foundation of China (Grant Nos. 21771012, 21601008 and 21576006)the National Natural Science Fund for Innovative Research Groups (Grant No. 51621003)the China Postdoctoral Science Foundation (Grant No. 2016M600879)
文摘The separation of gas molecules with similar physicochemical properties is of high importance but practically entails a substantial energy penalty in chemical industry. Meanwhile, clean energy gases such as H_2 and CH_4 are considered as promising candidates for the replacement of traditional fossil fuels. However, the technologies for the storage of these gases are still immature. In addition, the release of anthropogenic toxic gases into the atmosphere is a worldwide threat of growing concern. Both in academia and industry, considerable research efforts have been devoted to developing advanced porous materials for the effective and energy-efficient separation, storage, or capture of the related gases. In contrast to conventional inorganic porous materials such as zeolites and activated carbons, metal–organic frameworks(MOFs) are considered as a type of promising materials for gas separation and storage. In this contribution, we review the recent research advance of MOFs in some relevant applications, including CO_2 capture, O_2 purification, separation of light hydrocarbons, separation of noble gases, storage of gases(CH_4,H_2, and C_2 H_2) for energy, and removal of some gaseous air pollutants(NH_3, NO_2, and SO_2). Finally, an outlook regarding the challenges of the future research of MOFs in these directions is given.
基金Project 40472082 supported by the National Natural Science Foundation of China
文摘Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were investigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were analyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.
基金supported by the National Natural Science Foundation of China (No. 20973017 and 21077007)the Creative Research Foundation of Beijing University Technology (No. 00500054R4003)the Creative Research Team of Beijing Municipality (No. PHR201007105)
文摘Perovskite-like oxide La2-xSrxCuO4 （x = 0, 1） single crystallites with microrod-like morphologies and tetragonal crystal structures were prepared hydrothermally at 240 ℃ with poly（ethylene glycol） （PEG） or hexadecyltrimethyl ammonium bromide （CTAB） as a surfactant and after calcination at 850 ℃. The physicochemical properties of the materials were characterized by means of XRD, BET, SEM, TEM/SAED （selected-area electron diffraction）, XPS and H2-TPR techniques. It is found that doping Sr2＋ to La2CuO4 lattice enhanced the catalytic activity for methane combustion and the LaSrCuO4 catalyst derived from PEG is the best among the tested ones. It is concluded that factors, such as adsorbed oxygen species concentration, reducibility and surface area, determined the catalytic performance of such single-crystalline materials.
基金Project 06JK244 supported by the Special Foundation of Education Department of Shaanxi Province
文摘A thermogravimetric analysis (TG) was conducted to study the thermal decomposition behavior and kinetics of composites from coal and high density polyethylene (HDPE), linear low density polyethylene (LLDPE) or low density polyethylene (LDPE). The results show that coal facilitates melting of the polyethylene before temperatures reach 700 K in nitrogen due to the exothermic effect of coal. Above 700 K, adding coal into the polyethylene will result in smaller maximum rates of mass loss and higher initial mass loss temperatures of the composites. Hence, some chemical interactions, occurring between liquid compounds released in the pyrolysis of the coal and polymer, depend on several factors, such as coal rank and the molecular structure of polymers. Synergetic effects in coal and polymers were also found. Both chemical interactions and synergetic effects control the entire thermal decomposition behavior of compos- ites. The larger the amount of coal in the composites, the greater the decomposition temperature spans and the higher the maximum decomposition temperature, the smaller the devolatilization rates. The effect of coal on the thermal stability of composites lies in the hydrogen acceptor effect of the coals. Thermal decomposition of the coals, the polymers and related composites can be modelled via first order parallel reactions between 563 K and 763 K.
基金supported by the Natural Science Foundation of Henan Province (No.2004150017)the Leading Academic Discipline Project of Chemical Engineering of Henan University of Urban Construction
文摘The abundance of low-rank coals in China, such as bituminous and brown coals, makes studies of their composition and structure of great significance to both coal chemistry research and for efficient utilization of the coal. We describe how a Chinese brown coal was ultrasonically extracted with carbon disulfide （CS2） and the raw and extracted coals were characterized by Fourier Transform Infrared Spectroscopy （FTIR）. The corresponding extract was analyzed with a coupled gas chromatograph mass spectrometer （GC/MS）. The FTIR analysis shows a great abundance of amidocyanogen, carbonyl, aromatic and hetero aromatic rings and single carbon-beteroatom bonds. This suggests the possible occurrence of compounds like alcohols, phenols, amines, esters, carboxylic acids, ethers, aromatics or heteroaromatics. The GC/MS analysis of the CS2 extract detected 62 compounds, among which the non-polar ones were of lower abundance while the polar ones were in higher abundance and were structurally diverse. This demonstrates the compositional and structural complexity of Shengli coal.
基金supported by the Natural Science Foundation of Shaanxi Province,China(2013JM2009)
文摘In situ chemical oxidation polymerization of pyrrole on the surface of sulfur particles was carried out to synthesize a sulfur/polypyrrole （SIPPy） nanocomposite with core-shell structure. The composite was characterized by elemental analysis, X-ray diffraction, scanning/transmission electron microscopy, and electrochemical measurements. XRD and FTIR results showed that sulfur well dispersed in the core-shell structure and PPy structure was successfully obtained via in situ oxidative polymerization of pyrrole on the surface of sulfur particles. TEM observation revealed that PPy was formed and fixed to the surface of sulfur nanoparticle after polymerization, developing a well-defined core-shell structure and the thickness of PPy coating layer was in the range of 20-30 nm. In the composite, PPy worked as a conducting matrix as well as a coating agent, which confined the active materials within the electrode. Consequently, the as prepared SIPPy composite cathode exhibited good cycling and rate performances for rechargeable lithium/sulfur batteries. The resulting cell containing SIPPy composite cathode yields a discharge capacity of 1039 mAh·g^-1 at the initial cycle and retains 59% of this value over 50 cycles at 0.1 C rate. At 1 C rate, the SIPPy composite showed good cycle stability, and the discharge capacity was 475 mAh·g^-1 after 50 cycles.
基金financially supported by the National Natural Science Foundation of China (No.21371055)the Hunan Provincial Colleges and Universities Innovation Platform Open Fund Project (No.15K049)
文摘This paper has provided an effective method to utilize the flter residue. A Y zeolite-containing composite and a fuid catalytic cracking （FCC） catalyst had been successfully prepared by an in-situ crystallization technology using flter residue and kaolin as raw materials. The samples were characterized by XRD, FT-IR, SEM, and N2 adsorption-desorption techniques and evaluated in a bench FCC unit. In comparison to the reference samples synthesized from single kaolin, the silica/alumina molar ratio, the external surface area, and the total pore volume of the composite increased by 16.2%, 14.5%, and 16.2%, respectively. The catalyst possessed more meso- and macro-pores and more acid sites than the reference catalyst, and exhibited better coke selectivity. The prepared catalyst had the optimum isomerization and aromatization performance. The olefn content in the cracked gasoline obtained over this catalyst was reduced by 5.05 percentage points with the research octane number of gasoline increased by 0.5 units.
基金the Swedish Research Council (2016-06146,2019-02345)Swedish Research Council (grant no.2020-05223)+7 种基金the Swedish Research Council Formas,the Swedish Energy Agency (52473-1)the Wallenberg Foundation (2017.0186 and 2016.0059) for financial supportsupported by the National Research Foundation of Korea (NRF-2017M3A7B8065584 and 2020R1A4A1018516)Support from the National Natural Science Foundation of China (61774077)the Key Projects of Joint Fund of Basic and Applied Basic Research Fund of Guangdong Province (2019B1515120073)the Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology (No.2020B1212030010)Support from Sino-Danish Center for Education and ResearchSwedish Energy Agency (grant no.45420-1)
文摘All-polymer solar cells(all-PSCs)possess attractive merits including superior thermal stability and mechanical flexibility for large-area roll-to-roll processing.Introducing flexible conjugation-break spacers(FCBSs)into backbones of polymer donor(P_(D))or polymer acceptor(P_(A))has been demonstrated as an efficient approach to enhance both the photovoltaic(PV)and mechanical properties of the all-PSCs.However,length dependency of FCBS on certain all-PSC related properties has not been systematically explored.In this regard,we report a series of new non-conjugated P_(A)s by incorporating FCBS with various lengths(2,4,and 8 carbon atoms in thioalkyl segments).Unlike com-mon studies on so-called side-chain engineering,where longer side chains would lead to better solubility of those resulting polymers,in this work,we observe that the solubilities and the resulting photovoltaic/mechanical properties are optimized by a proper FCBS length(i.e.,C2)in P_(A) named PYTS-C2.Its all-PSC achieves a high efficiency of 11.37%,and excellent mechanical robustness with a crack onset strain of 12.39%,significantly superior to those of the other P_(A)s.These results firstly demonstrate the effects of FCBS lengths on the PV performance and mechanical properties of the all-PSCs,providing an effective strategy to fine-tune the structures of P_(A)s for highly efficient and mechanically robust PSCs.
基金supported by the National Natural Science Foundation of China (No. 21003103)the Nature Scientific Research Foundation of Shaanxi Provincial Education Office of China (No. 2010JS061)Natural Science Foundation Program of Yan’an University (YD2011-19)
文摘A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.
基金supported by the Korea Institute for Advancement of Technology (KIAT)the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (P0017363)the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT). (2023R1A2C1003312)。
文摘Herein,a facile synthetic strategy is proposed to fabricate high-performance electrocatalysts for rechargeable Zn-air batteries(ZABs).Heterostructured NiCo/NiCo_(2)S_(4) nanoparticles encapsulated in N-,S-co-doped CNT(NiCo/NiCo_(2)S_(4)@NSCNT) are synthesized via co-precipitation,thermal carbonization,and partial sulfidation processes.The strongly coupled NiCo/NiCo_(2)S_(4) heterostructure can improve the redox property and charge transfer ability.Also,the CNTs with abundant foreign dopants provide high electrical conductivity and abundant defect sites for both the oxygen evolution reaction(OER) and oxygen reduction reaction(ORR).The prepared NiCo/NiCo_(2)S_(4)@NSCNT electrocatalyst exhibits a low overpotential of 349 mV at a current density of 10 mA cm-2 and a half-wave potential of 0.865 V for the OER and ORR,respectively.Moreover,the ZAB assembled using as-prepared NiCo/NiCo_(2)S_(4)@NSCNT can provide superior specific capacity(756.16 mA h g_(Zn)^(-1)],peak power density(155.82 mW cm^(-2)),and long-term cyclability compared to those of the precious metal-based electrocatalyst(Pt/C+RuO_(2)).
基金supported by the National Natural Science Foundation of China(NSFC-2117622)
文摘Formic acid photodegradation is one of the most important reactions in organic pollution control, and helps to improve the hydrogen generation efficiency in titanium dioxide catalyzed water photodecomposition. Based on density functional theory and Reax FF molecular dynamics, the adsorption, diffusion and activation of formic acid on the different anatase TiO（101）,（001）,（010） surfaces are investigated.The result shows that the adsorption of COOH on anatase TiOsurface shrinks the energy gap between the dehydrogenation intermediate COOH and HCOO. On the anatase TiO（101） surface, the formic acid breaks the O–H bond at the first step with activation energy 0.24 eV, and the consequent break of α-H become much easier with activation energy 0.77 eV. The dissociation of α-H is the determination step of the HCOOH decomposition.
基金the support from National Natural Science Foundation of China under Grant No.11175157the Zhejiang Natural Science Foundations of China under No.LY16A050002+1 种基金521 Talent Project of Zhejiang Sci-Tech Universitythe Young Researchers Foundations of Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology
文摘In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.
基金provided by the National Natural Science Foundation of China(No.21371055)the Hunan provincial Natural Science Foundation of China(No.11JJ2008)the Hunan provincial Colleges and Universities Innovation Platform Open Fund Project(No.15K049)
文摘Novel composite material with a wide pore distribution was synthesized by an in situ technique using spent FCC catalyst as raw material. The characterization results indicated that the composite material contained 56.7% of zeolite Y and exhibited a much larger specific surface area and pore volume as well as strong hydrothermal stability. Fluid catalytic cracking(FCC) catalyst was prepared based on the composite material. The results indicated that the as-prepared catalyst possessed a unique pore structure that was advantageous to the diffusion-controlled reactions. In addition, the attrition resistance, activity and hydrothermal stability of the studied catalyst were superior to those of the reference catalyst. The catalyst also exhibited excellent nickel and vanadium passivation performance, strong bottoms upgrading selectivity, and better gasoline and coke selectivity. In comparison to the reference catalyst, the yields of the gasoline and light oil increased by 1.61 and 1.31 percentage points, respectively, and the coke yield decreased by 0.22 percentage points, and the olefin content in the produced gasoline reduced by 2.51 percentage points, with the research octane number increased by 0.7 unit.
文摘Production of ceramic armour solutions on-demand/in-theatre would have significant logistical and military advantages.However,even assuming that such technologies could be successfully deployed in the field,such near net-shape manufacturing technology is relatively immature compared to conventional sintering of ceramics.In this study,the ballistic performance of a series of additively manufactured(AM)/rapidly-prototyped(RP)alumina tiles of 97.2%of the density of Sintox FATM were investigated using both forward-and reverse-ballistic experiments.These experiments,undertaken with compressed gasguns,employed the depth-of-penetration technique and flash X-ray as primary diagnostics to interrogate both efficiency of penetration and projectile-target interaction,respectively.The RP alumina was found to exhibit useful ballistic properties,successfully defeating steel-cored(AP)7.62×39 mm BXN rounds at velocities of up-to c.a.850 m/s,while exhibiting comparable failure modes to conventionally sintered armour-grade Sintox FATM.However,where a<1%by vol.Cu dopant was introduced into the RP material failure modes changed dramatically with performance dropping below that of conventionally sintered alumina.Overall,the results from both sets of experiments were complimentary and clearly indicated the potential of such RP materials to play an active role in provision of real-world body armour solutions provided quality control of the RP material can be maintained.
文摘The effect of annealing on the microstructure and electrical characteristics of poly （3-hexylthiophene） （P3HT） films doped with very small amounts of the electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane （F4-TCNQ） is studied. X-ray diffraction and UV-vis spectrum studies show that unlike the pure P3HT film, the thermal treatment on the doped fihns under an Ar atmosphere can effectively enhance the crystalline order of P3HT films, as well as successfully facilitate the orientation of the polymer chains. This improvement is attributed to the electrostatic force between P3HT and F4-TCNQ molecules. This force induces the polymer chains to crystallize and orient during the annealing process. As a result, annealing significantly improves performance, especially for the Ion/Ioff ratio of the TFTs based on the doped P3HT films.
文摘Effects of dopant properties on microstructures and the electrical characteristics of poly （3-hexylthiophene） （P3HT） films are studied by doping 0.1 wt% 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane （F4？TCNQ）, 6,6-phenyl-C61butyric acid methyl ester （PCBM） and N,N＇？Diphenyl-N,N＇-（m-tolyl）-benzidine （TPD） into P3HT, respectively. The introductions of various dopants in small quantities increase the field-effect mobility and the I on/Ioff ratio of P3HT thin-film transistors. However, each of dopants shows various effects on the crystalline order and the molecular orientation of P3HT films and the performance of P3HT thin-film transistors. These can be attributed to the various size, shape and energy-level properties of the dopants.
基金supported by the projects of the Korea Electric Power Corporation(R19TA05)。
文摘Herein,incremental capacity-differential voltage (IC-DV) at a high C-rate (HC) is used as a non-invasive diagnostic tool in lithium-ion batteries,which inevitably exhibit capacity fading caused by multiple mechanisms during charge/discharge cycling.Because battery degradation modes are complex,the simple output of capacity fading does not yield any useful data in that respect.Although IC and DV curves obtained under restricted conditions (<0.1C,25℃) were applied in non-invasive analysis for accurate observation of degradation symptoms,a facile,rapid diagnostic approach without intricate,complex calculations is critical in on-board applications.Herein,Li Ni_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC532)/graphite pouch cells were cycled at 4 and 6C and the degradation characteristics,i.e.,loss of active materials (LAM) and loss of lithium inventory (LLI),were parameterized using the IC-DV curves.During the incremental current cycling,the initial steep LAM and LLI slopes underwent gradual transitions to gentle states and revealed the gap between low-and high-current measurements.A quantitative comparison of LAM at high and low C-rate showed that a IC;revealed the relative amount of available reaction region limited by cell polarization.However,this did not provide a direct relationship for estimating the LAM at a low C-rate.Conversely,the limiting LLI,which is calculated at a C-rate approaching 0,was obtained by extrapolating the LLI through more than two points measured at high C-rate,and therefore,the LLI at 0.1C was accurately determined using rapid cycling.
