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
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
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
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
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
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
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
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
The establishment of multi-component catalytic systems on Fe2O3 photoanodes presents considerable potential for significantly enhancing the performance of photoelectrochemical water splitting systems. In this study, w...The establishment of multi-component catalytic systems on Fe2O3 photoanodes presents considerable potential for significantly enhancing the performance of photoelectrochemical water splitting systems. In this study, we hydrothermally synthesized a Fe2O3 photoanode. In addition, d-Fe OOH synthesized via dip-coating and hydrothermally prepared h-FeOOH were used as cocatalysts and their synergistic combinations with cobalt phosphate(Co-Pi) were investigated. The synergy between h-FeOOH and Co-Pi was remarkable, whereas that between d-Fe OOH and Co-Pi was negligible. For example, the onset potentials of the Co-Pi/h-FeOOH and Co-Pi/d-FeOOH dual catalysts, were cathodically shifted by 270 and 170 m V, respectively. Moreover, the photocurrent density of the Co-Pi/h-FeOOH/Fe2O3 anode was significantly higher than that of the Co-Pi/d-FeOOH/Fe2O3 one. The synergistic effect of Co-Pi and h-FeOOH could be attributed to the significantly inhibited recombination of surface charges owing to the formation of a p-n junction between β-FeOOH and Fe2O3 and the large contact area between the granular h-FeOOH and Co-Pi. However, the thin amorphous FeOOH layer of the Co-Pi/d-FeOOH/Fe2O3 anode acted as a hole-transfer medium, and weakly promoted the kinetics of the charge transfer process.展开更多
Solid-state fiber dye-sensitized solar cells(SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks(MOFs) are one...Solid-state fiber dye-sensitized solar cells(SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks(MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency(PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO_(2)(mp-TiO_(2)) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices(4.19%).The MOF-801 enhanced SS-FDSSCs decreased the series resistance(R_(s)) value, resulting in effective electron extraction with improved short-circuit current density(J_(SC)), while also increasing the shunt resistance(R_(sh)) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.展开更多
Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized b...Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized by x-ray diffraction,scanning electron microscopy,and atomic force microscopy.The light absorption and photoelectric conversion properties were evaluated by the UV-visible absorption spectra and monochromatic incident photon-to-electron conversion efficiency.The chemical composition and element combination of the samples were examined by x-ray photoelectron spectroscopy.A linear sweep voltammetric and stability test(I-t)were performed with an electrochemical workstation.The results show that the samples are uniform with a thickness of approximately 800 nm and that the photoelectrochemical performance of the doped films is heavily dependent on the Fe source and dopant concentration.Upon optimizing the doping conditions of Fe(NO3)3 and the optimal source,the photocurrent density in the Fe-doped CuWO4 photoanode film is improved by 78%from 0.267 mA/cm2 to 0.476 mA/cm2 at 1.23 V vs reversible hydrogen electrode.The underlying causes are discussed.展开更多
Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this...Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this issue,iron doped vanadyl phosphate(Fe:VOPO_(4))was grafted on molybdenum doped BiVO_(4)(Mo:BiVO_(4))for significantly enhancing charge transfer and oxygen evolution kinetics simultaneously.Consequently,the resultant Fe:VOPO_(4)/Mo:BVO_(4) photoanode exhibits a remarkable photocurrent density of 6.59 mA cm^(-2) at 1.23 V versus the reversible hydrogen electrode(VRHE)under AM 1.5G illumination,over approximately 5.5 times as high as that of pristine BiVO_(4).Systematic studies have demonstrated that the hopping activation energy of small polarons is significantly reduced due to the Mo doping,resulting in accelerated bulk charge transfer.More importantly,the deposition of Fe:VOPO_(4) promotes the interfacial charge transfer between Mo:BiVO_(4) and Fe:VOPO_(4) via the construction of V-O-V and P-O bonds,in addition to facilitating water splitting kinetics.This work provides a general strategy for optimizing charge transfer process,especially at the interface between photoanodes and cocatalysts.展开更多
Photoelectrochemical syngas production using photoanode-driven systems from aqueous CO_(2) is a promising technology.To address the challenge of poor selectivity caused by the wide band gap of photoelectrode,we introd...Photoelectrochemical syngas production using photoanode-driven systems from aqueous CO_(2) is a promising technology.To address the challenge of poor selectivity caused by the wide band gap of photoelectrode,we introduce a novel photoanode,PDI/Cu_(2)O/Cu,where PDI is the perylene tetracarboxylic di-(propyl imidazole).Using Cu_(2)O as a substrate enhances charge transfer kinetics,while PDI modification mitigates photocorrosion and augments photoelectrochemical CO_(2) reduction reaction(PEC CO_(2)RR)activity.This enhancement stems from PDI’s narrow band gap and efficient visible light absorption.The syngas production achieved a noteworthy 124.47μmol/(cm^(2)·h)at 1.57 V vs.RHE,making it an optimal feedstock gas for hydrocarbon synthesis.Detailed UV-vis spectra indicate that layered structure significantly improves the absorption edge of the photoanode,facilitating enhanced utilization of visible light.Additionally,the electron lifetime of the PDI/Cu_(2)O/Cu photoanode is substantially increased which is also one of the factors affecting the reactivity,as demonstrated by the Bode phase plot.展开更多
Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the pr...Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.展开更多
Utilization of visible light is of crucial importance for exploiting efficient semiconductor catalysts for solar water splitting. In this study, an advanced ion implantation method was utilized to dope Cu ions into Zn...Utilization of visible light is of crucial importance for exploiting efficient semiconductor catalysts for solar water splitting. In this study, an advanced ion implantation method was utilized to dope Cu ions into ZnO nanorod arrays for photoelectrochemical water splitting in visible light. X-ray diffraction （XRD） and X-ray photo-electron spectroscopy （XPS） results revealed that Cu^＋ together with a small amount of Cu^2＋ were highly dispersed within the ZnO nanorod arrays. The Cu ion doped ZnO nanorod arrays displayed extended optical absorption and enhanced photoelectrochemical performance under visible light illumination （A 〉 420 nm）. A considerable photocurrent density of 18 μA/cm^2 at 0.8 V （vs. a saturated calomel electrode） was achieved, which was about 11 times higher than that of undoped ZnO nanorod arrays. This study proposes that ion implantation could be an effective approach for developing novel visible-light-driven photocatalytic materials for water splitting.展开更多
Silicon-based electrodes have attracted great attention in the artificial photosynthetic systems that mimic natural photosynthesis and directly convert the solar energy into chemical energy. Despite significant effort...Silicon-based electrodes have attracted great attention in the artificial photosynthetic systems that mimic natural photosynthesis and directly convert the solar energy into chemical energy. Despite significant efforts to date,catalytic stability of the silicon photoelectrodes is limited by their poor electrochemical stability. The formation of passivation or protective layers provides a feasible strategy to improve the photocatalytic stability of silicon photoelectrodes. Many candidates including metals, metal oxides, metal silicides and polymers have been explored as the protection layers for silicon photoelectrodes. The present review gives a concise overview of the protected silicon photoanodes for water oxidation with a focus on the relationship between the structural architecture of silicon photoanodes and their photocatalytic activity and stability.展开更多
Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous elect...Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous electrolytes. To overcome this challenge, most approaches have focused on improving the stability of Si by coating dense and thin protective layers using high vacuum-based techniques such as atomic layer deposition. However, these procedures are costly, making scalability for practical applications difficult. Herein, we report a modified electroless deposition （ELD） method to uniformly deposit protective and catalytic Ni films on Si wafers, resulting in efficient and stable Si photoanodes for solar water oxidation. The optimized Ni/n-Si photoanode achieves an onset potential of -1.09 V vs. a reversible hydrogen electrode and a saturation current density of -27.5 mA/cm^2 under AM 1.5 G illumination at pH 14. The ELD method is additionally capable of Ni deposition on a 4-inch n-Si wafer, demonstrating the first 4-inch Si photoanode. The solar water oxidation of the ELD-Ni/n-Si photoanode can be further improved by surface texturing, built-in n-p junctions, or coupling with more efficient catalysts.展开更多
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.
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.
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The establishment of multi-component catalytic systems on Fe2O3 photoanodes presents considerable potential for significantly enhancing the performance of photoelectrochemical water splitting systems. In this study, we hydrothermally synthesized a Fe2O3 photoanode. In addition, d-Fe OOH synthesized via dip-coating and hydrothermally prepared h-FeOOH were used as cocatalysts and their synergistic combinations with cobalt phosphate(Co-Pi) were investigated. The synergy between h-FeOOH and Co-Pi was remarkable, whereas that between d-Fe OOH and Co-Pi was negligible. For example, the onset potentials of the Co-Pi/h-FeOOH and Co-Pi/d-FeOOH dual catalysts, were cathodically shifted by 270 and 170 m V, respectively. Moreover, the photocurrent density of the Co-Pi/h-FeOOH/Fe2O3 anode was significantly higher than that of the Co-Pi/d-FeOOH/Fe2O3 one. The synergistic effect of Co-Pi and h-FeOOH could be attributed to the significantly inhibited recombination of surface charges owing to the formation of a p-n junction between β-FeOOH and Fe2O3 and the large contact area between the granular h-FeOOH and Co-Pi. However, the thin amorphous FeOOH layer of the Co-Pi/d-FeOOH/Fe2O3 anode acted as a hole-transfer medium, and weakly promoted the kinetics of the charge transfer process.
基金supported by the Fundamental Research Program(PNK 7350 and PNK 7340)of the Korea Institute of Materials Science(KIMS)the National Research Foundation(NRF)grant funded by the Korean government(MEST)(2021R1A2C2014192)。
文摘Solid-state fiber dye-sensitized solar cells(SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks(MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency(PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO_(2)(mp-TiO_(2)) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices(4.19%).The MOF-801 enhanced SS-FDSSCs decreased the series resistance(R_(s)) value, resulting in effective electron extraction with improved short-circuit current density(J_(SC)), while also increasing the shunt resistance(R_(sh)) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.
基金Project supported by the National Natural Science Foundation of China(Grant No.11204238)the Natural Science Foundation of Shaanxi Province,China(Grant No.2017JM1030).
文摘Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized by x-ray diffraction,scanning electron microscopy,and atomic force microscopy.The light absorption and photoelectric conversion properties were evaluated by the UV-visible absorption spectra and monochromatic incident photon-to-electron conversion efficiency.The chemical composition and element combination of the samples were examined by x-ray photoelectron spectroscopy.A linear sweep voltammetric and stability test(I-t)were performed with an electrochemical workstation.The results show that the samples are uniform with a thickness of approximately 800 nm and that the photoelectrochemical performance of the doped films is heavily dependent on the Fe source and dopant concentration.Upon optimizing the doping conditions of Fe(NO3)3 and the optimal source,the photocurrent density in the Fe-doped CuWO4 photoanode film is improved by 78%from 0.267 mA/cm2 to 0.476 mA/cm2 at 1.23 V vs reversible hydrogen electrode.The underlying causes are discussed.
基金supported by the National Natural Science Foundation of China(52373087,51973235,52173091,22208331 and 62274050)Program for Leading Talents of National Ethnic Affairs Commission of China(MZR21001)+2 种基金Hubei Provincial Natural Science Foundation of China(2021CFA022)Wuhan Science and Technology Bureau(2020010601012198)Zhejiang Provincial Natural Science Foundation of China under Grant No.LZ21E020002.
文摘Bismuth vanadate(BiVO_(4))is a promising photoanode material for photoelectrochemical(PEC)water oxidation.However,its performance is greatly hindered by poor bulk and interfacial charge transfer.Herein,to address this issue,iron doped vanadyl phosphate(Fe:VOPO_(4))was grafted on molybdenum doped BiVO_(4)(Mo:BiVO_(4))for significantly enhancing charge transfer and oxygen evolution kinetics simultaneously.Consequently,the resultant Fe:VOPO_(4)/Mo:BVO_(4) photoanode exhibits a remarkable photocurrent density of 6.59 mA cm^(-2) at 1.23 V versus the reversible hydrogen electrode(VRHE)under AM 1.5G illumination,over approximately 5.5 times as high as that of pristine BiVO_(4).Systematic studies have demonstrated that the hopping activation energy of small polarons is significantly reduced due to the Mo doping,resulting in accelerated bulk charge transfer.More importantly,the deposition of Fe:VOPO_(4) promotes the interfacial charge transfer between Mo:BiVO_(4) and Fe:VOPO_(4) via the construction of V-O-V and P-O bonds,in addition to facilitating water splitting kinetics.This work provides a general strategy for optimizing charge transfer process,especially at the interface between photoanodes and cocatalysts.
基金supported by the National Natural Science Foundation of China(No.22379054)Startup Funding at Jiangnan University.
文摘Photoelectrochemical syngas production using photoanode-driven systems from aqueous CO_(2) is a promising technology.To address the challenge of poor selectivity caused by the wide band gap of photoelectrode,we introduce a novel photoanode,PDI/Cu_(2)O/Cu,where PDI is the perylene tetracarboxylic di-(propyl imidazole).Using Cu_(2)O as a substrate enhances charge transfer kinetics,while PDI modification mitigates photocorrosion and augments photoelectrochemical CO_(2) reduction reaction(PEC CO_(2)RR)activity.This enhancement stems from PDI’s narrow band gap and efficient visible light absorption.The syngas production achieved a noteworthy 124.47μmol/(cm^(2)·h)at 1.57 V vs.RHE,making it an optimal feedstock gas for hydrocarbon synthesis.Detailed UV-vis spectra indicate that layered structure significantly improves the absorption edge of the photoanode,facilitating enhanced utilization of visible light.Additionally,the electron lifetime of the PDI/Cu_(2)O/Cu photoanode is substantially increased which is also one of the factors affecting the reactivity,as demonstrated by the Bode phase plot.
基金supported by the National Key Research and Development Program of China (2018YFA0209600)Shenzhen Peacock Plan (KQTD2016053015544057)Nanshan Pilot Plan (LHTD20170001)
文摘Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China （Nos. 51102194, 51323011, and 51121092）, the Doctoral Program of the Ministry of Education （No. 20110201120040） and the Nano Research Program of Suzhou City （ZXG2013003）. S. Shen is supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China （No. 201335） and the Fundamental Research Funds for the Central Universities.
文摘Utilization of visible light is of crucial importance for exploiting efficient semiconductor catalysts for solar water splitting. In this study, an advanced ion implantation method was utilized to dope Cu ions into ZnO nanorod arrays for photoelectrochemical water splitting in visible light. X-ray diffraction （XRD） and X-ray photo-electron spectroscopy （XPS） results revealed that Cu^＋ together with a small amount of Cu^2＋ were highly dispersed within the ZnO nanorod arrays. The Cu ion doped ZnO nanorod arrays displayed extended optical absorption and enhanced photoelectrochemical performance under visible light illumination （A 〉 420 nm）. A considerable photocurrent density of 18 μA/cm^2 at 0.8 V （vs. a saturated calomel electrode） was achieved, which was about 11 times higher than that of undoped ZnO nanorod arrays. This study proposes that ion implantation could be an effective approach for developing novel visible-light-driven photocatalytic materials for water splitting.
基金supported by the National Natural Science Foundation of China(21201138)the National Basic Research Program of China(2012CB619401)
文摘Silicon-based electrodes have attracted great attention in the artificial photosynthetic systems that mimic natural photosynthesis and directly convert the solar energy into chemical energy. Despite significant efforts to date,catalytic stability of the silicon photoelectrodes is limited by their poor electrochemical stability. The formation of passivation or protective layers provides a feasible strategy to improve the photocatalytic stability of silicon photoelectrodes. Many candidates including metals, metal oxides, metal silicides and polymers have been explored as the protection layers for silicon photoelectrodes. The present review gives a concise overview of the protected silicon photoanodes for water oxidation with a focus on the relationship between the structural architecture of silicon photoanodes and their photocatalytic activity and stability.
文摘Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous electrolytes. To overcome this challenge, most approaches have focused on improving the stability of Si by coating dense and thin protective layers using high vacuum-based techniques such as atomic layer deposition. However, these procedures are costly, making scalability for practical applications difficult. Herein, we report a modified electroless deposition （ELD） method to uniformly deposit protective and catalytic Ni films on Si wafers, resulting in efficient and stable Si photoanodes for solar water oxidation. The optimized Ni/n-Si photoanode achieves an onset potential of -1.09 V vs. a reversible hydrogen electrode and a saturation current density of -27.5 mA/cm^2 under AM 1.5 G illumination at pH 14. The ELD method is additionally capable of Ni deposition on a 4-inch n-Si wafer, demonstrating the first 4-inch Si photoanode. The solar water oxidation of the ELD-Ni/n-Si photoanode can be further improved by surface texturing, built-in n-p junctions, or coupling with more efficient catalysts.
