The photochemical conversion of plastic waste into valuable resources under ambient conditions is challenging.Achieving efficient photocatalytic conversion necessitates intimate contact between the photocatalyst and p...The photochemical conversion of plastic waste into valuable resources under ambient conditions is challenging.Achieving efficient photocatalytic conversion necessitates intimate contact between the photocatalyst and plastic substrate,as water molecules are readily oxidized by photogenerated holes,potentially bypassing the plastic as the electron donor.This study demonstrated a novel strategy for depositing polystyrene(PS)waste onto a photoanode by leveraging its solubility in specific organic solvents,including acetone and chloroform,thus enhancing the interface contact.We used an anodization technique to fabricate a skeleton-like porous tungsten oxide(WO_(3))structure,which exhibited higher durability against detachment from a conductive substrate than the WO_(3) photoanode fabricated using the doctor blade method.Upon illumination,the photogenerated holes were transferred from WO_(3) to PS,promoting the oxidative degradation of plastic waste under ambient conditions.Consequently,the oxidative degradation of PS on the anode side generated carbon dioxide,while the cathodic process produced hydrogen gas through water reduction.Our findings pave the way for sunlight-driven plastic waste treatment technologies that concurrently generate valuable fuels or chemicals and offer the dual benefits of cost savings and environmental protection.展开更多
Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity t...Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity to increase the PEC activity of BiVO_(4)by loading oxygen evolution co-catalysts(OECs)has been proven,however it suffers from sluggish charge carriers dynamics brought on by the complicated interface between BiVO_(4)and OECs as well as poor long-term durability.Herein,we connected OECs(NiFeOx)and photoanode with a Al-O bridge for bettering the PEC performance of BiVO_(4).The Al-O bridge served as a channel to extract hole from BiVO_(4)to Ni Fe Ox,thus boosting charge carriers separation and preventing BiVO_(4) from photo-corrosion.The Al-O bridging photoanode(NiFeO_(x)/Al_(2)O_(3)/BiVO_(4))demonstrated a high photocurrent density of 5.87 m A/cm^(2)at 1.23 V vs.RHE and long-term photostability in comparison to Ni Fe Ox/BiVO_(4)photoanode.This study proposes a unique technique to boost charge carriers separation between BiVO_(4) and OECs for high-efficiency solar-driven PEC water splitting.展开更多
This study first demonstrates the potential of organic photoabsorbing blends in overcoming a critical limitation of metal oxide photoanodes in tandem modules:insufficient photogenerated current.Various organic blends,...This study first demonstrates the potential of organic photoabsorbing blends in overcoming a critical limitation of metal oxide photoanodes in tandem modules:insufficient photogenerated current.Various organic blends,including PTB7-Th:FOIC,PTB7-Th:O6T-4F,PM6:Y6,and PM6:FM,were systematically tested.When coupled with electron transport layer(ETL)contacts,these blends exhibit exceptional charge separation and extraction,with PM6:Y6 achieving saturation photocurrents up to 16.8 mA cm^(-2) at 1.23 VRHE(oxygen evolution thermodynamic potential).For the first time,a tandem structure utilizing organic photoanodes has been computationally designed and fabricated and the implementation of a double PM6:Y6 photoanode/photovoltaic structure resulted in photogenerated currents exceeding 7mA cm^(-2) at 0 VRHE(hydrogen evolution thermodynamic potential)and anodic current onset potentials as low as-0.5 VRHE.The herein-presented organic-based approach paves the way for further exploration of different blend combinations to target specific oxidative reactions by selecting precise donor/acceptor candidates among the multiple existing ones.展开更多
Solar water splitting is an emerging technology for producing clean and renewable hydrogen fuel from sunlight and water.Among various photoelectrode materials,bismuth vanadate(BiVO_(4))has attracted considerable atten...Solar water splitting is an emerging technology for producing clean and renewable hydrogen fuel from sunlight and water.Among various photoelectrode materials,bismuth vanadate(BiVO_(4))has attracted considerable attention due to its visible light absorption,favorable band edge positions,good chemical stability,and low cost.However,the solar water splitting efficiency of BiVO_(4) photoanodes is still far from satisfactory,mainly because of the low charge carrier mobility,high recombination rate,and slow water oxidation kinetics.In this review,we summarize the recent progress in the synthesis,modification,and application of BiVO_(4)-based photoelectrodes for photoelectrochemical(PEC)water splitting.The working principle of PEC water splitting and the fundamental properties of BiVO_(4) are introduced.Then,the synthesis methods of BiVO_(4) films are reviewed,and the strategies to enhance the PEC properties of BiVO_(4) are critically discussed.Furthermore,the applications of BiVO_(4)-based photoelectrodes in different scenarios are highlighted.Finally,the summary and outlook for the future development of BiVO_(4)-based photoelectrodes for PEC water splitting are presented.展开更多
The slow-proton-fast-electron process severely limits the catalytic efficiency of oxygen evolution reaction.A method is proposed to accelerate proton transfer by building up local electric fields.Modifying acetic,etha...The slow-proton-fast-electron process severely limits the catalytic efficiency of oxygen evolution reaction.A method is proposed to accelerate proton transfer by building up local electric fields.Modifying acetic,ethanedioic and propanetricarboxylic(C_(6)H_(8)O_(6))ligands on BiVO_(4)surface results in a potential difference between BiVO_(4)and ligands that generates a local electric field which serves as a driving force for proton transfer.Among the ligands,carrying the strongest electron-withdrawing ability,the modification of C_(6)H_(8)O_(6) forms the strongest local electric field and leads to the fastest proton transfer and the smallest thermodynamic overpotential.C_(6)H_(8)O_(6)-BiVO_(4)exhibits 3.5 times photocurrent density as high as that of pure BiVO_(4),which is 3.50 mA cm^(-2)at 1.23 VRHE.The onset potential of C_(6)H_(8)O_(6)-BiVO_(4)shifts negatively from 0.70 to 0.38 VRHE.The mechanism for OER transitions from thermodynamically high energy proton-coupled electron transfer to thermodynamically low energy electron transfer as proton transfer is accelerated.展开更多
A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic（PEC） reduction of CO2 into formic acid（HCOOH）. The films prepared by doctor blade method were characterized with X-ray diffractometer...A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic（PEC） reduction of CO2 into formic acid（HCOOH）. The films prepared by doctor blade method were characterized with X-ray diffractometer（XRD）, scanning electron microscope（SEM） and transmission electron microscope（TEM）. The existence of oxygen vacancies in the WO3-x was confirmed with an X-ray photoelectron spectroscopy（XPS）, and the accurate oxygen index was determined by a modified potentiometric titrimetry method. After 3h of photoelectrocatalytic reduction, the formic acid yield of the WO3-x/TiO2 film is 872 nmol/cm^2, which is 1.83 times that of the WO3/TiO2 film. The results of PEC performance demonstrate that the introduction of WO3-x nanoparticles can improve the charge transfer performance so as to enhance the performance of PEC reduction of CO2 into formic acid.展开更多
Photoelectrochemical(PEC)water splitting capable of reducing and oxidizing water into hydrogen and oxygen in a generation mode of spatial separation has gained extensive popularity.In order to effectively produce hydr...Photoelectrochemical(PEC)water splitting capable of reducing and oxidizing water into hydrogen and oxygen in a generation mode of spatial separation has gained extensive popularity.In order to effectively produce hydrogen at the photocathode of a PEC cell,the photoanode,where the oxygen evolution reaction occurs,should be systematically developed on priority.In particular,WO3 has been identified as one of the most promising photoanode materials owing to its narrow band gap and high valence band position.Its practical implementation,however,is still limited by excessive electron–hole recombination and poor water oxidation kinetics.This review presents the various strategies that have been studied for enhancing the PEC water oxidation performance of WO3,such as controlling the morphology,introducing defects,constructing a heterojunction,loading a cocatalyst,and exploiting the plasmonic effect.In addition,the possible future research directions are presented.展开更多
Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode ...Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode is manufactured by depositing plasmonic nanoparticles of the non-noble metal Al on the surface of a TiO2/Cu2O core/shell heterojunction for the first time.The Al nanoparticles,which exhibit a surface plasmon resonance(SPR)effect and are substantially less expensive than noble metals such as Au and Ag,generate hot electron-hole pairs and amplify the electromagnetic field at the interface under illumination.The as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and transfer.Their photocurrent density of 4.52 mA·cm^-2 at 1.23 V vs.RHE represents an 1.84-fold improvement over that of TiO2/Cu2O.Specifically,the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its stability.In this work,the synergistic effect of the heterojunctions and the SPR effect of the non-noble metal Al significantly improve the photoelectrode performance,providing a novel concept for the design of electrodes with good properties and high practicability.展开更多
The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） ...The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.展开更多
A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOO...A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOOH,M=Fe,Co,Ni)as a model system,we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction(OER).Among the photoanodes with the three different electrocatalysts,the best OER activity,with a low-onset potential of∼1.01 VRHE,a high photocurrent density of 24.10 mA cm^(-2)at 1.23 VRHE,and a remarkable saturation photocurrent density of 38.82 mA cm^(-2),was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight(100 mW cm^(-2))in 1 M KOH electrolyte.The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport,provides a larger number of surface active sites,and results in higher OER activity,compared to other electrocatalysts.This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.展开更多
A versatile phase transformation strategy was proposed to synthesize novel BiVO4 nanosheets(NSs)@WO3 nanorod(NR)and nanoplate(NP)arrays films.The strategy was carried out by following a three-step hydrothermal process...A versatile phase transformation strategy was proposed to synthesize novel BiVO4 nanosheets(NSs)@WO3 nanorod(NR)and nanoplate(NP)arrays films.The strategy was carried out by following a three-step hydrothermal process(WO3→WO3/Bi2WO6→WO3/BiVO4).According to the characterization results,plenty of BiVO4 NSs grew well on the surface of WO3 NR and NP arrays films,thus forming the WO3/BiVO4 heterojunction structure.The prepared WO3/BiVO4 heterojunction films were used as the photoanodes for the photoelectrochemical(PEC)water splitting.As indicated by the results,the photoanodes exhibited an excellent PEC activity.The photocurrent densities of the WO3/BiVO4 NR and NP photoanodes at 1.23 V(vs RHE)without cocatalyst under visible light illumination reached up to about 1.56 and 1.20 mA/cm2,respectively.展开更多
A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can ...A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.展开更多
With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was ...With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was prepared by anodic aluminum oxide (AAO) templateassisted electrochemical deposition route.Then,Ag nanowires were coated by TiO2 nanoparticles in hydrothermal process.The structures of the photoanode were characterized by field emission scanning electron microscopy (FESEM).Ag nanowires are covered by a layer of very fine nanoparticles with a diameter of less than 5 nm.X-ray diffraction (XRD) and selected-area electron diffraction (SAED) show that Ag nanowires have a strong preferred orientation in (220) direction and the TiO2 coating layer is a polycrystalline structure.With this photoanode,3.2 % conversion efficiency is achieved for the cell sensitized with N3 dye.展开更多
A novel Sb2O3/Sb2S3/FeOOH photoanode was fabricated via a simple solution impregnation method along with chemical bath deposition and post-sulfidation.The X-ray diffractometry,Raman measurement,and X-ray photoelectron...A novel Sb2O3/Sb2S3/FeOOH photoanode was fabricated via a simple solution impregnation method along with chemical bath deposition and post-sulfidation.The X-ray diffractometry,Raman measurement,and X-ray photoelectron spectroscopy show that the Sb2O3/Sb2S3/FeOOH thin films are successfully prepared.SEM−EDS analyses reveal that the surface of Sb2O3/Sb2S3 thin films becomes rough after the immersion in the FeCl3 solution.The optimized impregnation time is found to be 8 h.The FeOOH co-catalyst loaded Sb2O3/Sb2S3 electrode exhibits an enhanced photocurrent density of 0.45 mA/cm2 at 1.23 V versus RHE under simulated 1 sun,which is approximately 1.41 times compared to the photocurrent density of the unloaded one.Through the further tests of UV−Vis spectroscopy,the electrochemical impedance spectra,and the PEC measurements,the enhancement can result from the increased light-harvesting ability,the decreased interface transmission impedance,and the remarkably enhanced carrier injection efficiency.展开更多
Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelect...Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water splitting.However,its PEC performance is severely hindered owing to poor surface charge transfer,surface recombination at the photoanode/electrolyte junction,and sluggish oxygen evolution reaction(OER)kinetics.In this regard,a novel solution was developed in this study to address these issues by decorating the surface of BiVO_(4)with cobalt sulfide,whose attractive features such as low cost,high conductivity,and rapid charge-transfer ability assisted in improving the PEC activity of the BiVO_(4)photoanode.The fabricated photoanode exhibited a significantly enhanced photocurrent density of 3.2 m A cm^(-2)under illumination at 1.23 V vs.a reversible hydrogen electrode,which is more than 2.5 times greater than that of pristine BiVO_(4).Moreover,the Co S/BiVO_(4)photoanode also exhibited considerable improvements in the charge injection yield(75.8%vs.36.7%for the bare BiVO_(4)film)and charge separation efficiency(79.8%vs.66.8%for the pristine BiVO_(4)film).These dramatic enhancements were primarily ascribed to rapid charge-transport kinetics and efficient reduction of the anodic overpotential for oxygen evolution enabled by the surface modification of BiVO_(4)by Co S.This study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.展开更多
Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of p...Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.展开更多
Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was sign...Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was significantly improved because of covalent bonds in the interfaces between the film and substrate,while only weak Van der Waals bonds existed at the interfaces within the particle-assembledβ-Fe_(2)O_(3)film prepared by electrophoretic deposition.The as-prepared planar films were thus able to withstand higher annealing temperature and stronger laser irradiation power in comparison with theβ-Fe_(2)O_(3)particle-assembly.Ti^(4+)doping was used to increase the concentration of carriers in the metastableβ-Fe_(2)O_(3)film.Compared with pureβ-Fe_(2)O_(3)photoanodes,the highest saturated photocurrent for water splitting over the Ti^(4+)-dopedβ-Fe_(2)O_(3)photoanode was increased by a factor of approximately three.Theβ-Fe_(2)O_(3)photoanode exhibited photochemical stability for water splitting for a duration exceeding 100 h,which indicates its important potential application in solar energy conversion.展开更多
Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of inte...Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of interfacial Z-scheme charge transfer still remain a significant challenge.Hence,in this study,CdS/Ti-Fe_(2)O_(3)heterojunction photoanodes are elaborately designed to explore the charge-transfer behavior in PEC water splitting.In this study,photophysical measurements,including the Kelvin probe measurement,surface photovoltage spectroscopy(SPV),and transient photovoltage spectroscopy(TPV),are used to monitor the migration behavior of photogenerated charges at the interface electric field of CdS/Ti-Fe_(2)O_(3)Z-scheme heterojunction photoanodes.The Kelvin probe and SPV measurements demonstrate that CdS/Ti-Fe_(2)O_(3)interfacial driving force favors the rapid transfer of photoexcited electrons to CdS.The double-beam strategy based on TPV indicates that more electrons of Ti-Fe_(2)O_(3)are combined with the holes of CdS owing to the intensive interface electric field.The results of these measurements successfully prove the Z-scheme migration mechanism of CdS/Ti-Fe_(2)O_(3)photoanodes.Benefiting from the desirable charge transfer at the interface electric field,CdS/Ti-Fe_(2)O_(3)photoanodes exhibit superior photocatalytic oxygen evolution reaction performance compared with that of pure Ti-Fe_(2)O_(3).The photocurrent density of the 25CdS/Ti-Fe_(2)O_(3)photoanode reaches 1.94 mA/cm^(2) at 1.23 V versus reversible hydrogen electrode without excess cocatalyst,and it is two times higher than that of pure Ti-Fe_(2)O_(3)photoanode.Therefore,an outstanding strategy is provided in this study to prove the Z-scheme charge-transfer mechanism of photocatalytic systems in PEC water splitting.展开更多
Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology...Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology still suffers from limited contact interfaces.In this study,the chemical vapor deposition(CVD)technique was for the first time used to construct the CdS/MoS_(2)heterojunction photoanode with a unique core-shell nanoarchitecture,in which a continuous crystalline MoS_(2)nanosheet layer was grown directly on one-dimensional(1D)oriented CdS nanorods(NRs)in a plane-to-plane stacking fashion.The optimization of junction thickness with adjustable MoS_(2)loading from mono to a few layers was achieved by experimental parameters variation.Systematic characterizations show that the MoS_(2)shell plays a dual role as an optical absorption booster for more photo-exciton generation and a surface passivator of trap states.Meanwhile,the formed heterojunction helps regulate the unidirectional charge migration for a significantly suppressed electron-hole recombination process,which synergistically contributes to higher quantum yield and efficiency.As a result,the optimized CdS/MoS_(2)heterojunction photoanode with 3-layered MoS_(2)wrapping exhibits the highest photocurrent density and photoconversion efficiency,over a two-fold increase,compared to those of pristine CdS and the previously reported CdS/MoS_(2)hetero-junctions.Moreover,due to the rapid hole extraction from CdS and transferred surface oxidation sites,the present CdS/MoS_(2)heterostructure demonstrates better corrosion resistance and higher photostability.The present work is expected to provide a versatile platform for exploiting the CVD technique to develop other MoS_(2)-based heterojunction photoelectrodes with extensive PEC applications.展开更多
BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical applications.However,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfacto...BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical applications.However,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical performance.To address this,various modifications have been attempted,including the use of ferroelectric materials.Ferroelectric materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole pairs.In this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of BFO.The self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge recombination.As a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)analysis.These results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.展开更多
基金supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and Information and Communication Technology(ICT)(NRF-2020M3H4A3106354)Korea Government(MSIT,RS-2023-00213022)the Korea Institution of Science and Technology(KIST)internal projects.
文摘The photochemical conversion of plastic waste into valuable resources under ambient conditions is challenging.Achieving efficient photocatalytic conversion necessitates intimate contact between the photocatalyst and plastic substrate,as water molecules are readily oxidized by photogenerated holes,potentially bypassing the plastic as the electron donor.This study demonstrated a novel strategy for depositing polystyrene(PS)waste onto a photoanode by leveraging its solubility in specific organic solvents,including acetone and chloroform,thus enhancing the interface contact.We used an anodization technique to fabricate a skeleton-like porous tungsten oxide(WO_(3))structure,which exhibited higher durability against detachment from a conductive substrate than the WO_(3) photoanode fabricated using the doctor blade method.Upon illumination,the photogenerated holes were transferred from WO_(3) to PS,promoting the oxidative degradation of plastic waste under ambient conditions.Consequently,the oxidative degradation of PS on the anode side generated carbon dioxide,while the cathodic process produced hydrogen gas through water reduction.Our findings pave the way for sunlight-driven plastic waste treatment technologies that concurrently generate valuable fuels or chemicals and offer the dual benefits of cost savings and environmental protection.
基金financially supported by the National Natural Science Foundation of China(No.52173277)the Fundamental Research Funds for the Central Universities of Chang’an University(No.300102299304)+1 种基金the Innovative Research Team for Science and Technology of Shaanxi Province(No.2022TD-04)the open program of Key Laboratories of Fine Chemicals and Surfactants in Sichuan Provincial Universities(No.2023JXZ03)。
文摘Developing BiVO_(4)photoanode with efficient carrier transfer and fast water oxidation kinetics is the permanent pursuit to achieve the state-of-art solar-driven photoelectrochemical(PEC)water splitting.The capacity to increase the PEC activity of BiVO_(4)by loading oxygen evolution co-catalysts(OECs)has been proven,however it suffers from sluggish charge carriers dynamics brought on by the complicated interface between BiVO_(4)and OECs as well as poor long-term durability.Herein,we connected OECs(NiFeOx)and photoanode with a Al-O bridge for bettering the PEC performance of BiVO_(4).The Al-O bridge served as a channel to extract hole from BiVO_(4)to Ni Fe Ox,thus boosting charge carriers separation and preventing BiVO_(4) from photo-corrosion.The Al-O bridging photoanode(NiFeO_(x)/Al_(2)O_(3)/BiVO_(4))demonstrated a high photocurrent density of 5.87 m A/cm^(2)at 1.23 V vs.RHE and long-term photostability in comparison to Ni Fe Ox/BiVO_(4)photoanode.This study proposes a unique technique to boost charge carriers separation between BiVO_(4) and OECs for high-efficiency solar-driven PEC water splitting.
基金partly funded by a BIST Ignite Programme grant from the Barcelona Institute of Science and Technology(Code:MOLOPEC)financial support from LICROX and SOREC2 EUFunded projects(Codes:951843 and 101084326)+7 种基金the BIST Program,and Severo Ochoa Programpartially funded by CEX2019-000910-S(MCIN/AEI/10.13039/501100011033 and PID2020-112650RBI00),Fundació Cellex,Fundació Mir-PuigGeneralitat de Catalunya through CERCAfunding from the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101081441financial support by the Agencia Estatal de Investigación(grant PRE2018-084881)the financial support by from the European Union’s Horizon Europe research and innovation programme under the Marie Skłodowska-Curie grant agreement No 101081441support from the MCIN/AEI JdC-F Fellowship(FJC2020-043223-I)the Severo Ochoa Excellence Postdoctoral Fellowship(CEX2019-000910-S).
文摘This study first demonstrates the potential of organic photoabsorbing blends in overcoming a critical limitation of metal oxide photoanodes in tandem modules:insufficient photogenerated current.Various organic blends,including PTB7-Th:FOIC,PTB7-Th:O6T-4F,PM6:Y6,and PM6:FM,were systematically tested.When coupled with electron transport layer(ETL)contacts,these blends exhibit exceptional charge separation and extraction,with PM6:Y6 achieving saturation photocurrents up to 16.8 mA cm^(-2) at 1.23 VRHE(oxygen evolution thermodynamic potential).For the first time,a tandem structure utilizing organic photoanodes has been computationally designed and fabricated and the implementation of a double PM6:Y6 photoanode/photovoltaic structure resulted in photogenerated currents exceeding 7mA cm^(-2) at 0 VRHE(hydrogen evolution thermodynamic potential)and anodic current onset potentials as low as-0.5 VRHE.The herein-presented organic-based approach paves the way for further exploration of different blend combinations to target specific oxidative reactions by selecting precise donor/acceptor candidates among the multiple existing ones.
基金financially supported by the National Natural Science Foundation of China(No.52372292)Shenzhen Science and Technology Program(No.JCYJ20220530161615035)+1 种基金the Fundamental Research Funds for the Central Universitiesthe International Science and Technology Cooperation Program of Henan Province(No.232102520018).
文摘Solar water splitting is an emerging technology for producing clean and renewable hydrogen fuel from sunlight and water.Among various photoelectrode materials,bismuth vanadate(BiVO_(4))has attracted considerable attention due to its visible light absorption,favorable band edge positions,good chemical stability,and low cost.However,the solar water splitting efficiency of BiVO_(4) photoanodes is still far from satisfactory,mainly because of the low charge carrier mobility,high recombination rate,and slow water oxidation kinetics.In this review,we summarize the recent progress in the synthesis,modification,and application of BiVO_(4)-based photoelectrodes for photoelectrochemical(PEC)water splitting.The working principle of PEC water splitting and the fundamental properties of BiVO_(4) are introduced.Then,the synthesis methods of BiVO_(4) films are reviewed,and the strategies to enhance the PEC properties of BiVO_(4) are critically discussed.Furthermore,the applications of BiVO_(4)-based photoelectrodes in different scenarios are highlighted.Finally,the summary and outlook for the future development of BiVO_(4)-based photoelectrodes for PEC water splitting are presented.
文摘The slow-proton-fast-electron process severely limits the catalytic efficiency of oxygen evolution reaction.A method is proposed to accelerate proton transfer by building up local electric fields.Modifying acetic,ethanedioic and propanetricarboxylic(C_(6)H_(8)O_(6))ligands on BiVO_(4)surface results in a potential difference between BiVO_(4)and ligands that generates a local electric field which serves as a driving force for proton transfer.Among the ligands,carrying the strongest electron-withdrawing ability,the modification of C_(6)H_(8)O_(6) forms the strongest local electric field and leads to the fastest proton transfer and the smallest thermodynamic overpotential.C_(6)H_(8)O_(6)-BiVO_(4)exhibits 3.5 times photocurrent density as high as that of pure BiVO_(4),which is 3.50 mA cm^(-2)at 1.23 VRHE.The onset potential of C_(6)H_(8)O_(6)-BiVO_(4)shifts negatively from 0.70 to 0.38 VRHE.The mechanism for OER transitions from thermodynamically high energy proton-coupled electron transfer to thermodynamically low energy electron transfer as proton transfer is accelerated.
基金Project(21471054)supported by the National Natural Science Foundation of China
文摘A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic（PEC） reduction of CO2 into formic acid（HCOOH）. The films prepared by doctor blade method were characterized with X-ray diffractometer（XRD）, scanning electron microscope（SEM） and transmission electron microscope（TEM）. The existence of oxygen vacancies in the WO3-x was confirmed with an X-ray photoelectron spectroscopy（XPS）, and the accurate oxygen index was determined by a modified potentiometric titrimetry method. After 3h of photoelectrocatalytic reduction, the formic acid yield of the WO3-x/TiO2 film is 872 nmol/cm^2, which is 1.83 times that of the WO3/TiO2 film. The results of PEC performance demonstrate that the introduction of WO3-x nanoparticles can improve the charge transfer performance so as to enhance the performance of PEC reduction of CO2 into formic acid.
基金financially supported by the National Natural Science Foundation of China (21808189, 21663027)the Science and Technology Support Project of Gansu Province (1504GKCA027)+2 种基金the Program for Innovative Research Team (NWNULKQN-15-2)the Opening Project of Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control (GKLECPC-12)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education (LYJ18205)~~
文摘Photoelectrochemical(PEC)water splitting capable of reducing and oxidizing water into hydrogen and oxygen in a generation mode of spatial separation has gained extensive popularity.In order to effectively produce hydrogen at the photocathode of a PEC cell,the photoanode,where the oxygen evolution reaction occurs,should be systematically developed on priority.In particular,WO3 has been identified as one of the most promising photoanode materials owing to its narrow band gap and high valence band position.Its practical implementation,however,is still limited by excessive electron–hole recombination and poor water oxidation kinetics.This review presents the various strategies that have been studied for enhancing the PEC water oxidation performance of WO3,such as controlling the morphology,introducing defects,constructing a heterojunction,loading a cocatalyst,and exploiting the plasmonic effect.In addition,the possible future research directions are presented.
文摘Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water splitting.Here,a novel TiO2/Cu2O/Al/Al2O3 photoelectrode is manufactured by depositing plasmonic nanoparticles of the non-noble metal Al on the surface of a TiO2/Cu2O core/shell heterojunction for the first time.The Al nanoparticles,which exhibit a surface plasmon resonance(SPR)effect and are substantially less expensive than noble metals such as Au and Ag,generate hot electron-hole pairs and amplify the electromagnetic field at the interface under illumination.The as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and transfer.Their photocurrent density of 4.52 mA·cm^-2 at 1.23 V vs.RHE represents an 1.84-fold improvement over that of TiO2/Cu2O.Specifically,the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its stability.In this work,the synergistic effect of the heterojunctions and the SPR effect of the non-noble metal Al significantly improve the photoelectrode performance,providing a novel concept for the design of electrodes with good properties and high practicability.
基金the financial support from Iranian Nanotechnology Society and Isfahan University of Technology (IUT) Research Council
文摘The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.
文摘A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical(PEC)water splitting is central to improving its performance.Herein,taking the Si-based photoanodes(n^(+)p-Si/SiO_(x)/Fe/FeOx/MOOH,M=Fe,Co,Ni)as a model system,we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction(OER).Among the photoanodes with the three different electrocatalysts,the best OER activity,with a low-onset potential of∼1.01 VRHE,a high photocurrent density of 24.10 mA cm^(-2)at 1.23 VRHE,and a remarkable saturation photocurrent density of 38.82 mA cm^(-2),was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight(100 mW cm^(-2))in 1 M KOH electrolyte.The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport,provides a larger number of surface active sites,and results in higher OER activity,compared to other electrocatalysts.This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(21808051,51904356,21703062).
文摘A versatile phase transformation strategy was proposed to synthesize novel BiVO4 nanosheets(NSs)@WO3 nanorod(NR)and nanoplate(NP)arrays films.The strategy was carried out by following a three-step hydrothermal process(WO3→WO3/Bi2WO6→WO3/BiVO4).According to the characterization results,plenty of BiVO4 NSs grew well on the surface of WO3 NR and NP arrays films,thus forming the WO3/BiVO4 heterojunction structure.The prepared WO3/BiVO4 heterojunction films were used as the photoanodes for the photoelectrochemical(PEC)water splitting.As indicated by the results,the photoanodes exhibited an excellent PEC activity.The photocurrent densities of the WO3/BiVO4 NR and NP photoanodes at 1.23 V(vs RHE)without cocatalyst under visible light illumination reached up to about 1.56 and 1.20 mA/cm2,respectively.
基金supported by the National Natural Science Foundation of China(21663027,51262028,21261021)the Science and Technology Support Project of Gansu Province(1504GKCA027)+2 种基金the Program for the Young Innovative Talents of Longyuanthe Program for Innovative Research Team(NWNULKQN-15-2)the Undergraduate Academic Innovative Research Team of Northwest Normal University~~
文摘A bismuth vanadate(BiVO4)photoanode with a cocatalyst consisting of NiFe layered double‐hydroxide(NiFe‐LDH)nanoparticles was fabricated for photoelectrochemical(PEC)water splitting.NiFe‐LDH nanoparticles,which can improve light‐absorption capacities and facilitate efficient hole transfer to the surface,were deposited on the surface of the BiVO4 photoanode by a hydrothermal method.All the samples were characterized using X‐ray diffraction,scanning electron microscopy,and diffuse‐reflectance spectroscopy.Linear sweep voltammetry and current‐time plots were used to investigate the PEC activity.The photocurrent response of NiFe‐LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4,Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible‐light illumination.NiFe‐LDH/BiVO4 also gave a superior PEC hydrogen evolution performance.Furthermore,the stability of the NiFe‐LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode,and offers a novel method for solar‐assisted water splitting.
基金financially supported by the National Natural Science Foundation of China(No.51301041)
文摘With the aim of reducing series resistance and increasing dye loading,novel dye-sensitized solar cell architecture was designed with TiO2 nanoparticle-coated Ag nanowires array as the photoanode.Ag nanowire array was prepared by anodic aluminum oxide (AAO) templateassisted electrochemical deposition route.Then,Ag nanowires were coated by TiO2 nanoparticles in hydrothermal process.The structures of the photoanode were characterized by field emission scanning electron microscopy (FESEM).Ag nanowires are covered by a layer of very fine nanoparticles with a diameter of less than 5 nm.X-ray diffraction (XRD) and selected-area electron diffraction (SAED) show that Ag nanowires have a strong preferred orientation in (220) direction and the TiO2 coating layer is a polycrystalline structure.With this photoanode,3.2 % conversion efficiency is achieved for the cell sensitized with N3 dye.
基金Project(51674298)supported by the National Natural Science Foundation of ChinaProject(2017JJ3384)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2018M630910)supported by the China Postdoctoral Science Foundation。
文摘A novel Sb2O3/Sb2S3/FeOOH photoanode was fabricated via a simple solution impregnation method along with chemical bath deposition and post-sulfidation.The X-ray diffractometry,Raman measurement,and X-ray photoelectron spectroscopy show that the Sb2O3/Sb2S3/FeOOH thin films are successfully prepared.SEM−EDS analyses reveal that the surface of Sb2O3/Sb2S3 thin films becomes rough after the immersion in the FeCl3 solution.The optimized impregnation time is found to be 8 h.The FeOOH co-catalyst loaded Sb2O3/Sb2S3 electrode exhibits an enhanced photocurrent density of 0.45 mA/cm2 at 1.23 V versus RHE under simulated 1 sun,which is approximately 1.41 times compared to the photocurrent density of the unloaded one.Through the further tests of UV−Vis spectroscopy,the electrochemical impedance spectra,and the PEC measurements,the enhancement can result from the increased light-harvesting ability,the decreased interface transmission impedance,and the remarkably enhanced carrier injection efficiency.
文摘Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water splitting.However,its PEC performance is severely hindered owing to poor surface charge transfer,surface recombination at the photoanode/electrolyte junction,and sluggish oxygen evolution reaction(OER)kinetics.In this regard,a novel solution was developed in this study to address these issues by decorating the surface of BiVO_(4)with cobalt sulfide,whose attractive features such as low cost,high conductivity,and rapid charge-transfer ability assisted in improving the PEC activity of the BiVO_(4)photoanode.The fabricated photoanode exhibited a significantly enhanced photocurrent density of 3.2 m A cm^(-2)under illumination at 1.23 V vs.a reversible hydrogen electrode,which is more than 2.5 times greater than that of pristine BiVO_(4).Moreover,the Co S/BiVO_(4)photoanode also exhibited considerable improvements in the charge injection yield(75.8%vs.36.7%for the bare BiVO_(4)film)and charge separation efficiency(79.8%vs.66.8%for the pristine BiVO_(4)film).These dramatic enhancements were primarily ascribed to rapid charge-transport kinetics and efficient reduction of the anodic overpotential for oxygen evolution enabled by the surface modification of BiVO_(4)by Co S.This study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.
基金Natural Science Foundation of Zhejiang Province,Grant/Award Number:LY23E020002National Natural Science Foundation of China,Grant/Award Number:52272085 and 51972178+1 种基金Natural Science Foundation of Ningbo,Grant/Award Number:2021J145China Postdoctoral Science Foundation,Grant/Award Number:2020M681966。
文摘Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental issues.In a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC process.Then,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible substrates.Finally,some prospects concerning the challenges and research directions in this area are proposed.
文摘Planar films of pure and Ti^(4+)-dopedβ-Fe_(2)O_(3)were prepared by a spray pyrolysis method.X-ray diffraction patterns and Raman spectra of the metastableβ-Fe_(2)O_(3)film showed that its thermal stability was significantly improved because of covalent bonds in the interfaces between the film and substrate,while only weak Van der Waals bonds existed at the interfaces within the particle-assembledβ-Fe_(2)O_(3)film prepared by electrophoretic deposition.The as-prepared planar films were thus able to withstand higher annealing temperature and stronger laser irradiation power in comparison with theβ-Fe_(2)O_(3)particle-assembly.Ti^(4+)doping was used to increase the concentration of carriers in the metastableβ-Fe_(2)O_(3)film.Compared with pureβ-Fe_(2)O_(3)photoanodes,the highest saturated photocurrent for water splitting over the Ti^(4+)-dopedβ-Fe_(2)O_(3)photoanode was increased by a factor of approximately three.Theβ-Fe_(2)O_(3)photoanode exhibited photochemical stability for water splitting for a duration exceeding 100 h,which indicates its important potential application in solar energy conversion.
文摘Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of interfacial Z-scheme charge transfer still remain a significant challenge.Hence,in this study,CdS/Ti-Fe_(2)O_(3)heterojunction photoanodes are elaborately designed to explore the charge-transfer behavior in PEC water splitting.In this study,photophysical measurements,including the Kelvin probe measurement,surface photovoltage spectroscopy(SPV),and transient photovoltage spectroscopy(TPV),are used to monitor the migration behavior of photogenerated charges at the interface electric field of CdS/Ti-Fe_(2)O_(3)Z-scheme heterojunction photoanodes.The Kelvin probe and SPV measurements demonstrate that CdS/Ti-Fe_(2)O_(3)interfacial driving force favors the rapid transfer of photoexcited electrons to CdS.The double-beam strategy based on TPV indicates that more electrons of Ti-Fe_(2)O_(3)are combined with the holes of CdS owing to the intensive interface electric field.The results of these measurements successfully prove the Z-scheme migration mechanism of CdS/Ti-Fe_(2)O_(3)photoanodes.Benefiting from the desirable charge transfer at the interface electric field,CdS/Ti-Fe_(2)O_(3)photoanodes exhibit superior photocatalytic oxygen evolution reaction performance compared with that of pure Ti-Fe_(2)O_(3).The photocurrent density of the 25CdS/Ti-Fe_(2)O_(3)photoanode reaches 1.94 mA/cm^(2) at 1.23 V versus reversible hydrogen electrode without excess cocatalyst,and it is two times higher than that of pure Ti-Fe_(2)O_(3)photoanode.Therefore,an outstanding strategy is provided in this study to prove the Z-scheme charge-transfer mechanism of photocatalytic systems in PEC water splitting.
文摘Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology still suffers from limited contact interfaces.In this study,the chemical vapor deposition(CVD)technique was for the first time used to construct the CdS/MoS_(2)heterojunction photoanode with a unique core-shell nanoarchitecture,in which a continuous crystalline MoS_(2)nanosheet layer was grown directly on one-dimensional(1D)oriented CdS nanorods(NRs)in a plane-to-plane stacking fashion.The optimization of junction thickness with adjustable MoS_(2)loading from mono to a few layers was achieved by experimental parameters variation.Systematic characterizations show that the MoS_(2)shell plays a dual role as an optical absorption booster for more photo-exciton generation and a surface passivator of trap states.Meanwhile,the formed heterojunction helps regulate the unidirectional charge migration for a significantly suppressed electron-hole recombination process,which synergistically contributes to higher quantum yield and efficiency.As a result,the optimized CdS/MoS_(2)heterojunction photoanode with 3-layered MoS_(2)wrapping exhibits the highest photocurrent density and photoconversion efficiency,over a two-fold increase,compared to those of pristine CdS and the previously reported CdS/MoS_(2)hetero-junctions.Moreover,due to the rapid hole extraction from CdS and transferred surface oxidation sites,the present CdS/MoS_(2)heterostructure demonstrates better corrosion resistance and higher photostability.The present work is expected to provide a versatile platform for exploiting the CVD technique to develop other MoS_(2)-based heterojunction photoelectrodes with extensive PEC applications.
基金supported by the program of Future Hydrogen Original Technology Development(2021M3I3A1084747),through the National Research Foundation of Korea(NRF)funded by the Korean government(Ministry of Science and ICT(MSIT))by the NRF grant funded by the Korea government(MSIT)(No.2020R1A2C1005590)。
文摘BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical applications.However,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical performance.To address this,various modifications have been attempted,including the use of ferroelectric materials.Ferroelectric materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole pairs.In this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of BFO.The self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge recombination.As a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)analysis.These results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.
