Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provid...Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.展开更多
An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(C...An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(Ce6)and triethoxy(1H,1H,2H,2H‑nonafluorohexyl)silane(TFS)was coated on the outer layer of UC,and then a layer of HKUST‑1 shell was coated.The obtained nanocomposite UC@Ce6/TFS@mSiO_(2)@HKUST‑1(noted as UCTSH)was used for the synergistic treatment of chemodynamic therapy(CDT)and photodynamic therapy(PDT).Interestingly,the nanostructures can specifically re lease Cu^(2+)in the acidic tumor microenvironment.Cu^(2+)reacts with excess hydrogen peroxide(H_(2)O_(2))in the tumor microenvironment to form cytotoxic hydroxyl radical.Secondly,Ce6,with the action of oxygen‑carrying TFS,selectively produces a large amount of singlet oxygen by 808 nm laser irradiation.UCTSH can enhance the anti‑tumor effects of PDT and CDT by increasing the production level of reactive oxygen species,without causing damage to normal cells.展开更多
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul...The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.展开更多
The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.Th...The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.The complex was characterized by IR,^(1)H(^(13)C)NMR,elemental analysis,and powder X-ray diffraction,and the crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system with space group Iba2,and the central tin atom is in a five-coordinated trigonal bipyramidal configuration.Quantum chemistry ab initio calculations were performed to investigate the stability,molecular orbital energy,and frontier molecular orbital characteristics of the complex.Additionally,its thermal stability,electrochemical properties,and in vitro anticancer activity were evaluated.CCDC:2380308.展开更多
Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling perf...Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.展开更多
This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared...This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared to conventional stabilizers 2-nitrodiphenylamine (2-NDPA) and 1,3-dimethyl-1,3-diphenylurea (C-II). FTIR analysis confirms lignin's capacity to scavenge nitroxyl radicals formed during thermolysis of nitrocarbamate and nitrate ester bonds, thereby inhibiting decomposition. Moreover, the incorporation of C-II, 2-NDPA, and lignin significantly raised the peak temperature of the main thermolysis, as confirmed by DSC and TGA, indicating a progressive stability enhancement in the order: NCC/DEGDN < NCC/DEGDN/C-II < NCC/DEGDN/lignin < NCC/DEGDN/2-NDPA. Additionally, the effect of each stabilizer on the decomposition pathway was characterized by TGA-FTIR. The findings show that stabilizer type significantly affects the intensity of gaseous products released during decomposition without altering their nature. Notably, NH2 groups formed during NCC degradation play a key role in nitrogen conversion, particularly by reducing toxic NO emissions.展开更多
The corrosive electrochemistry of jamesonite was studied by cyclic voltammetry. Every peak in voltammograms was identified through thermodynamic calculation. The results show an irreversible electrode process by the s...The corrosive electrochemistry of jamesonite was studied by cyclic voltammetry. Every peak in voltammograms was identified through thermodynamic calculation. The results show an irreversible electrode process by the strong adsorption of oxidation elemental sulfur on jamesonite. A deficient-metal and sulfur-rich compound is formed under the potential of 80 mV at pH 6.86. The passive action by elemental sulfur occurs from 80 to 470 mV and S2O2-3, SO2-4 are produced at potential over 470 mV. The anodic peak producing SO2-4 is inhibited due to the deposition of PbSO4 at higher potential in Na2SO4 solution. The corrosive action of jamesonite becomes strong and the redox characterization similar to PbS, FeS and Sb2S3 appears at pH 9.18.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
The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has...The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.展开更多
In this study,a self-calibrating near-infrared fluorescence probe was designed and synthesized based on the dual-fluorophore strategy utilizing methylene blue and coumarin.The probe utilized methylene blue(emission sp...In this study,a self-calibrating near-infrared fluorescence probe was designed and synthesized based on the dual-fluorophore strategy utilizing methylene blue and coumarin.The probe utilized methylene blue(emission spectrum range:640-740 nm)and coumarin fluorophore(emission spectrum range:440-600 nm)as signal output units,thereby achieving effective spectral separation and highly selective detection of HClO.Under physiological pH conditions,HClO triggers an oxidation-cleavage reaction,releasing methylene blue and coumarin,which emit distinct red and green fluorescence,respectively.This dual-emission feature enabled rapid HClO detection with two-channel detection limits of 25.13 nmol·L^(-1)(green channel)and 31.55 nmol·L^(-1)(red channel).Furthermore,in cell imaging experiments,this probe demonstrated excellent cell membrane permeability and low cytotoxicity,successfully enabling the monitoring of both endogenous and exogenous HClO in living cells.By incorporating a twochannel self-calibration system,the probe effectively mitigated signal variations caused by instrumental or environmental interference,substantially improving detection sensitivity and reliability.展开更多
Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aq...Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.展开更多
Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-d...Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as guest molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.展开更多
In the near-infrared(NIR)spectroscopic data of complex sample systems,such as tobacco leaves,nonlinearity is fairly significant between the absorbance and concentration.This nonlinearity severely degrades the quantita...In the near-infrared(NIR)spectroscopic data of complex sample systems,such as tobacco leaves,nonlinearity is fairly significant between the absorbance and concentration.This nonlinearity severely degrades the quantitative results of traditional methods,such as partial least squares regression(PLS),which can be used to construct linear models.The problem was addressed in this study by using deep learning(DL).We employed three different DL models:a one-dimensional convolutional neural network(1D CNN),a deep neural network(DNN),and a stacked autoencoder with feedforward neural networks(SAE-FNNs).By carefully selecting and tuning the architectures and parameters of these models,we were able to find the most suitable model for dealing with such nonlinear relationships.Our experimental findings reveal that both the DNN and the SAE-FNN models excel in addressing the nonlinear issues of pectin concentration in tobacco,surpassing the performance of the classic linear model(PLS).Specifically,the DNN model stands out for its low average root mean squared error of prediction(RMSEP)value and small standard deviation(SD)of RMSEPs,leading to a tighter and more centered distribution of residuals in the prediction set.These DL models not only proficiently identify complex patterns within NIR data but also boast high prediction accuracy and fast implementation,demonstrating their effectiveness in analytical applications.展开更多
Magnesium alloys are promising candidates for bio-implant applications due to their biodegradability and biocompati-bility.However,their rapid corrosion remains a critical limitation.This study presents the developmen...Magnesium alloys are promising candidates for bio-implant applications due to their biodegradability and biocompati-bility.However,their rapid corrosion remains a critical limitation.This study presents the development of a multifunctional nanocomposite coating designed to enhance the corrosion resistance and antibacterial properties of magnesium alloy im-plants.The coating comprisedγ-cyclodextrin metal-organic frameworks(γ-CD MOFs)decorated with TiO_(2)@Ag core-shell nanoparticles,embedded in a polycaprolactone(PCL)matrix.Immersion tests in a simulated body fluid(SBF)revealed an initially higher corrosion rate for the PCL-TiO_(2)@Ag/γ-CD MOF coating compared to the coating without TiO_(2)@Ag nanopar-ticles;however,it demonstrated significant improvement over time.After five days,the corrosion inhibition reached 95.44%,with the corrosion rate decreasing to 1.70 mpy.Additionally,the composite coating exhibited strong antibacterial activity against Escherichia coli,Pseudomonas,and Staphylococcus aureus.Furthermore,MTT assays indicated that the coating facili-tated the growth and proliferation of osteoblast-like MC3T3-E1 cells,confirming its nontoxicity and biocompatibility.These findings highlight the potential of the PCL-TiO_(2)@Ag/γ-CD MOF nanocomposite as a biocompatible,antibacterial,and cor-rosion-resistant coating for biodegradable magnesium implants,offering a promising solution for biomedical applications.展开更多
Ras proteins,which are important for cellular signaling and cancer development,are activated by guanine nucleotide exchange factors,among which son-of-sevenless(Sos)plays a pivotal role.The catalytic activity of Sos i...Ras proteins,which are important for cellular signaling and cancer development,are activated by guanine nucleotide exchange factors,among which son-of-sevenless(Sos)plays a pivotal role.The catalytic activity of Sos is regulated by its interaction with Ras·GTP at the allosteric site of Sos.Although much research has been conducted,the structural details of the dynamic interactions between Ras·GTP and Sos at the allosteric site in solution are not completely understood.In this study,paramagnetic relaxation enhancement(PRE)was used to examine the binding of HRas·GTP to the allosteric site of Soscat.A site-specific paramagnetic probe was attached to Soscat,revealing crucial interface information,which was then used to build structural models of the HRas-Soscat complex via HADDOCK.Our results indicate that the dominant conformation of HRas·GTP bound to Soscat at the allosteric site is highly consistent with the established crystal structure while also identifying a transient conformation with a novel interface between HRas and Sos unseen in previous crystal structures.展开更多
Two new complexes,[Zn_(2)(L1)(HL1)(NO_(3))]·CH_(3)OH(1)and[Zn_(3)(L2)(L3)_(3)Cl]·CH_(3)OH(2),were successfully synthesized by‘one-pot’method based on cinnoline-3-ylhydrazine ligand and zinc with 2-hydroxy-...Two new complexes,[Zn_(2)(L1)(HL1)(NO_(3))]·CH_(3)OH(1)and[Zn_(3)(L2)(L3)_(3)Cl]·CH_(3)OH(2),were successfully synthesized by‘one-pot’method based on cinnoline-3-ylhydrazine ligand and zinc with 2-hydroxy-4-methoxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde ligands,respectively,where H_(2)L1=5-methoxy-2-(phthalazin-1-ylhydrazonomethyl)-phenol,H_(2)L2=2-methoxy-6-(phthalazin-1-yl-hydrazonomethyl)-phenol,HL3=2-(1,8-dihydro-[1,2,4]triazolo[3,4-α]phthalazin-3-yl)-6-methoxy-phenol.Complexes 1 and 2 were characterized by infrared spectroscopy,elemental analysis,single-crystal X-ray diffraction,powder X-ray diffraction,etc.It is worth noting that the cinnolin-3-yl-hydrazine ligand and 2-hydroxy-3-methoxybenzaldehyde form two types of Schiff bases(H_(2)L2 and HL3)when in situ reacting and coordinating with Zn(Ⅱ),and HL3 also has two coordination modes.In addition,the fluorescence performance showed that complex 1 can achieve selective and sensitive sensing of Al^(3+)in water with a detection limit of 6.37μmol·L^(-1).CCDC:2413978,1;2413979,2.展开更多
Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dio...Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dioxide and their subsequent photocatalytic use for the removal of three wastewater pollutants:diclofenac(DF),carbofuran(CB)and methylene blue(MB).The results show the following decreases(RE)in the initial concentrations of these pollutants,REDF=99.5%,REMB=96%and RECB=90%after 90 min of exposure to UV-Vis radiation using~0.6 mg of photocatalyst.Experiments also showed that the degradation rate of diclofenac(k=0.1028 min^(−1))is respectively 3.5 and 6 times faster than the values for CB(k=0.0298 min^(−1))and MB(k=0.0174 min^(−1)),probably due to the easier bond cleavage in DF.UV-Vis irradiated solutions of these pollutants were then analyzed by mass spectrometry to identify the species formed during photocatalysis and suggest possible degradation paths for MB,DF,and CB.Data showed that the degradation of DF involves the formation of a photocyclization product through loss of HCl molecule,clearly consuming less energy than that needed for the opening of the central aromatic ring in MB,or the loss of the N-methyl amide functional group for CB.展开更多
This feature article illustrates the potential of polarization modulation infrared reflection absorption spectroscopy(PM IRRAS)to provide molecular-level information about the structure,orientation and conformation of...This feature article illustrates the potential of polarization modulation infrared reflection absorption spectroscopy(PM IRRAS)to provide molecular-level information about the structure,orientation and conformation of constituents of thin films at electrode surfaces.PM IRRAS relies on the surface selection rules stating that the p-polarized IR beam is enhanced,while the s-polarized beam is attenuated at the metal surface.The difference between p-and s-polarized beams eliminates the background of the solvent and provides IR spectra at a single electrode potential.In contrast,two other popular in situ IR spectroscopic techniques,namely,subtractively normalized interfacial Fourier transform infrared spectroscopy(SNIFTIRS)and surface-enhanced infrared reflection absorption spectroscopy(SEIRAS),provide potential difference spectra to remove the signal from the bulk solution.In this feature article,we provide a brief tutorial on how to run the PM IRRAS experiment and describe the methods used for background elimination first.The application of the PM IRRAS in the biomimetic research is then illustrated by three examples:construction of a tethered bilayer,reconstitution of colicin into a phospholipid bilayer and determination of the orientation of nucleolipids in a monolayer assembled at a gold electrode surface.Finally,the structural changes of graphene oxide during its electrochemical reduction are described to highlight the promising application of PM IRRAS in materials science.展开更多
A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefo...A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.展开更多
With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lign...With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.展开更多
基金Support by National Natural Science Foundation of China(22127802,22573091)the HY Action(62402010305)。
文摘Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.
文摘An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(Ce6)and triethoxy(1H,1H,2H,2H‑nonafluorohexyl)silane(TFS)was coated on the outer layer of UC,and then a layer of HKUST‑1 shell was coated.The obtained nanocomposite UC@Ce6/TFS@mSiO_(2)@HKUST‑1(noted as UCTSH)was used for the synergistic treatment of chemodynamic therapy(CDT)and photodynamic therapy(PDT).Interestingly,the nanostructures can specifically re lease Cu^(2+)in the acidic tumor microenvironment.Cu^(2+)reacts with excess hydrogen peroxide(H_(2)O_(2))in the tumor microenvironment to form cytotoxic hydroxyl radical.Secondly,Ce6,with the action of oxygen‑carrying TFS,selectively produces a large amount of singlet oxygen by 808 nm laser irradiation.UCTSH can enhance the anti‑tumor effects of PDT and CDT by increasing the production level of reactive oxygen species,without causing damage to normal cells.
文摘The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.
文摘The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.The complex was characterized by IR,^(1)H(^(13)C)NMR,elemental analysis,and powder X-ray diffraction,and the crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system with space group Iba2,and the central tin atom is in a five-coordinated trigonal bipyramidal configuration.Quantum chemistry ab initio calculations were performed to investigate the stability,molecular orbital energy,and frontier molecular orbital characteristics of the complex.Additionally,its thermal stability,electrochemical properties,and in vitro anticancer activity were evaluated.CCDC:2380308.
基金supported by National Natural Science Foundation of China(52472194)the Deanship of Research and Graduate Studies at King Khalid University through Large Research Project(RGP-2/687/46).
文摘Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.
文摘This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared to conventional stabilizers 2-nitrodiphenylamine (2-NDPA) and 1,3-dimethyl-1,3-diphenylurea (C-II). FTIR analysis confirms lignin's capacity to scavenge nitroxyl radicals formed during thermolysis of nitrocarbamate and nitrate ester bonds, thereby inhibiting decomposition. Moreover, the incorporation of C-II, 2-NDPA, and lignin significantly raised the peak temperature of the main thermolysis, as confirmed by DSC and TGA, indicating a progressive stability enhancement in the order: NCC/DEGDN < NCC/DEGDN/C-II < NCC/DEGDN/lignin < NCC/DEGDN/2-NDPA. Additionally, the effect of each stabilizer on the decomposition pathway was characterized by TGA-FTIR. The findings show that stabilizer type significantly affects the intensity of gaseous products released during decomposition without altering their nature. Notably, NH2 groups formed during NCC degradation play a key role in nitrogen conversion, particularly by reducing toxic NO emissions.
文摘The corrosive electrochemistry of jamesonite was studied by cyclic voltammetry. Every peak in voltammograms was identified through thermodynamic calculation. The results show an irreversible electrode process by the strong adsorption of oxidation elemental sulfur on jamesonite. A deficient-metal and sulfur-rich compound is formed under the potential of 80 mV at pH 6.86. The passive action by elemental sulfur occurs from 80 to 470 mV and S2O2-3, SO2-4 are produced at potential over 470 mV. The anodic peak producing SO2-4 is inhibited due to the deposition of PbSO4 at higher potential in Na2SO4 solution. The corrosive action of jamesonite becomes strong and the redox characterization similar to PbS, FeS and Sb2S3 appears at pH 9.18.
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The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.
文摘In this study,a self-calibrating near-infrared fluorescence probe was designed and synthesized based on the dual-fluorophore strategy utilizing methylene blue and coumarin.The probe utilized methylene blue(emission spectrum range:640-740 nm)and coumarin fluorophore(emission spectrum range:440-600 nm)as signal output units,thereby achieving effective spectral separation and highly selective detection of HClO.Under physiological pH conditions,HClO triggers an oxidation-cleavage reaction,releasing methylene blue and coumarin,which emit distinct red and green fluorescence,respectively.This dual-emission feature enabled rapid HClO detection with two-channel detection limits of 25.13 nmol·L^(-1)(green channel)and 31.55 nmol·L^(-1)(red channel).Furthermore,in cell imaging experiments,this probe demonstrated excellent cell membrane permeability and low cytotoxicity,successfully enabling the monitoring of both endogenous and exogenous HClO in living cells.By incorporating a twochannel self-calibration system,the probe effectively mitigated signal variations caused by instrumental or environmental interference,substantially improving detection sensitivity and reliability.
基金partially supported by the National Natural Science Foundation of China(22479022)Liaoning Revitalization Talents Program(XLYC2007129)。
文摘Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.
文摘Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as guest molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.
基金supported by a joint project with SINOPEC(Dalian)Research Institute of Petroleum and Petrochemicals Co.,Ltd.(Contract No.323061).
文摘In the near-infrared(NIR)spectroscopic data of complex sample systems,such as tobacco leaves,nonlinearity is fairly significant between the absorbance and concentration.This nonlinearity severely degrades the quantitative results of traditional methods,such as partial least squares regression(PLS),which can be used to construct linear models.The problem was addressed in this study by using deep learning(DL).We employed three different DL models:a one-dimensional convolutional neural network(1D CNN),a deep neural network(DNN),and a stacked autoencoder with feedforward neural networks(SAE-FNNs).By carefully selecting and tuning the architectures and parameters of these models,we were able to find the most suitable model for dealing with such nonlinear relationships.Our experimental findings reveal that both the DNN and the SAE-FNN models excel in addressing the nonlinear issues of pectin concentration in tobacco,surpassing the performance of the classic linear model(PLS).Specifically,the DNN model stands out for its low average root mean squared error of prediction(RMSEP)value and small standard deviation(SD)of RMSEPs,leading to a tighter and more centered distribution of residuals in the prediction set.These DL models not only proficiently identify complex patterns within NIR data but also boast high prediction accuracy and fast implementation,demonstrating their effectiveness in analytical applications.
文摘Magnesium alloys are promising candidates for bio-implant applications due to their biodegradability and biocompati-bility.However,their rapid corrosion remains a critical limitation.This study presents the development of a multifunctional nanocomposite coating designed to enhance the corrosion resistance and antibacterial properties of magnesium alloy im-plants.The coating comprisedγ-cyclodextrin metal-organic frameworks(γ-CD MOFs)decorated with TiO_(2)@Ag core-shell nanoparticles,embedded in a polycaprolactone(PCL)matrix.Immersion tests in a simulated body fluid(SBF)revealed an initially higher corrosion rate for the PCL-TiO_(2)@Ag/γ-CD MOF coating compared to the coating without TiO_(2)@Ag nanopar-ticles;however,it demonstrated significant improvement over time.After five days,the corrosion inhibition reached 95.44%,with the corrosion rate decreasing to 1.70 mpy.Additionally,the composite coating exhibited strong antibacterial activity against Escherichia coli,Pseudomonas,and Staphylococcus aureus.Furthermore,MTT assays indicated that the coating facili-tated the growth and proliferation of osteoblast-like MC3T3-E1 cells,confirming its nontoxicity and biocompatibility.These findings highlight the potential of the PCL-TiO_(2)@Ag/γ-CD MOF nanocomposite as a biocompatible,antibacterial,and cor-rosion-resistant coating for biodegradable magnesium implants,offering a promising solution for biomedical applications.
基金supported by the Fundamental Research Funds for the Central Universities(WK9100000046).
文摘Ras proteins,which are important for cellular signaling and cancer development,are activated by guanine nucleotide exchange factors,among which son-of-sevenless(Sos)plays a pivotal role.The catalytic activity of Sos is regulated by its interaction with Ras·GTP at the allosteric site of Sos.Although much research has been conducted,the structural details of the dynamic interactions between Ras·GTP and Sos at the allosteric site in solution are not completely understood.In this study,paramagnetic relaxation enhancement(PRE)was used to examine the binding of HRas·GTP to the allosteric site of Soscat.A site-specific paramagnetic probe was attached to Soscat,revealing crucial interface information,which was then used to build structural models of the HRas-Soscat complex via HADDOCK.Our results indicate that the dominant conformation of HRas·GTP bound to Soscat at the allosteric site is highly consistent with the established crystal structure while also identifying a transient conformation with a novel interface between HRas and Sos unseen in previous crystal structures.
文摘Two new complexes,[Zn_(2)(L1)(HL1)(NO_(3))]·CH_(3)OH(1)and[Zn_(3)(L2)(L3)_(3)Cl]·CH_(3)OH(2),were successfully synthesized by‘one-pot’method based on cinnoline-3-ylhydrazine ligand and zinc with 2-hydroxy-4-methoxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde ligands,respectively,where H_(2)L1=5-methoxy-2-(phthalazin-1-ylhydrazonomethyl)-phenol,H_(2)L2=2-methoxy-6-(phthalazin-1-yl-hydrazonomethyl)-phenol,HL3=2-(1,8-dihydro-[1,2,4]triazolo[3,4-α]phthalazin-3-yl)-6-methoxy-phenol.Complexes 1 and 2 were characterized by infrared spectroscopy,elemental analysis,single-crystal X-ray diffraction,powder X-ray diffraction,etc.It is worth noting that the cinnolin-3-yl-hydrazine ligand and 2-hydroxy-3-methoxybenzaldehyde form two types of Schiff bases(H_(2)L2 and HL3)when in situ reacting and coordinating with Zn(Ⅱ),and HL3 also has two coordination modes.In addition,the fluorescence performance showed that complex 1 can achieve selective and sensitive sensing of Al^(3+)in water with a detection limit of 6.37μmol·L^(-1).CCDC:2413978,1;2413979,2.
基金MIUR,Italian Ministry for University and Research(EX-60%/2024)。
文摘Buckypapers(BPs)consist of carbon nanotube(CNT)membranes with good mechanical,thermal and elec-trical properties.We report the modification of CNT buckypapers by the surface deposition of a thin layer of ti-tanium dioxide and their subsequent photocatalytic use for the removal of three wastewater pollutants:diclofenac(DF),carbofuran(CB)and methylene blue(MB).The results show the following decreases(RE)in the initial concentrations of these pollutants,REDF=99.5%,REMB=96%and RECB=90%after 90 min of exposure to UV-Vis radiation using~0.6 mg of photocatalyst.Experiments also showed that the degradation rate of diclofenac(k=0.1028 min^(−1))is respectively 3.5 and 6 times faster than the values for CB(k=0.0298 min^(−1))and MB(k=0.0174 min^(−1)),probably due to the easier bond cleavage in DF.UV-Vis irradiated solutions of these pollutants were then analyzed by mass spectrometry to identify the species formed during photocatalysis and suggest possible degradation paths for MB,DF,and CB.Data showed that the degradation of DF involves the formation of a photocyclization product through loss of HCl molecule,clearly consuming less energy than that needed for the opening of the central aromatic ring in MB,or the loss of the N-methyl amide functional group for CB.
基金This research was funded by Discovery Grants from the Natural Sciences and Engineering Research Council of Canada(JL:RGPIN-2022-03958AC:RGPIN-2022-04238).
文摘This feature article illustrates the potential of polarization modulation infrared reflection absorption spectroscopy(PM IRRAS)to provide molecular-level information about the structure,orientation and conformation of constituents of thin films at electrode surfaces.PM IRRAS relies on the surface selection rules stating that the p-polarized IR beam is enhanced,while the s-polarized beam is attenuated at the metal surface.The difference between p-and s-polarized beams eliminates the background of the solvent and provides IR spectra at a single electrode potential.In contrast,two other popular in situ IR spectroscopic techniques,namely,subtractively normalized interfacial Fourier transform infrared spectroscopy(SNIFTIRS)and surface-enhanced infrared reflection absorption spectroscopy(SEIRAS),provide potential difference spectra to remove the signal from the bulk solution.In this feature article,we provide a brief tutorial on how to run the PM IRRAS experiment and describe the methods used for background elimination first.The application of the PM IRRAS in the biomimetic research is then illustrated by three examples:construction of a tethered bilayer,reconstitution of colicin into a phospholipid bilayer and determination of the orientation of nucleolipids in a monolayer assembled at a gold electrode surface.Finally,the structural changes of graphene oxide during its electrochemical reduction are described to highlight the promising application of PM IRRAS in materials science.
基金support from the Ministry of Higher Education Malaysia under grant HICOE-2023-005.
文摘A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.
基金National Natural Science Foundation of China(22262034)。
文摘With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.
