Nonstoichiometric In-S group yielding efficient carrier transfer pathway in In_(2)S_(3) photoanode for solar water oxidation

The construction of high-efficiency photoanodes is essential for developing outstanding photoelectrochemical(PEC)water splitting cells.Furthermore,insufficient carrier transport capabilities and sluggish surface water oxidation kinetics limit its application.Using a solvothermal annealing strategy,we prepared a nonstoichiometric In-S(NS)group on the surface of an In_(2)S_(3) photoanode in situ and unexpectedly formed a type II transfer path of carrier,thereby reducing the interfacial recombination and promoting the bulk separation.Firstprinciples calculations and comprehensive characterizations demonstrated NS group as an excellent oxygen evolution cocatalyst(OEC)that effectively facilitated carrier transport,lowered the surface overpotential,increased the surface active site,and accelerated the surface oxygen evolution reaction kinetics by precisely altering the rate-determining steps of*to*OH and*O to*OOH.These synergistic effects remarkably enhanced the PEC performance,with a high photocurrent density of 5.02 mA cm^(−2)at 1.23 V versus reversible hydrogen electrode and a negative shift in the onset potential by 310 mV.This work provides a new strategy for the in situ preparation of high-efficiency OECs and provides ideas for constructing excellent carrier transfer and transport channels.

TiO2 ALD decorated CuO/BiVO4 p-n heterojunction for improved photoelectrochemical water splitting

Bismuth vanadate(BiVO4)is a promising photoanode material owing to the narrow bandgap,appropriate band position,and excellent resistance against photocorrosion,however,the performance of photoelectrochemical(PEC)water splitting is largely limited by the poor carrier separation and transport ability.To address these issues,for the first time,we fabricate BiVO4 film/CuO nanocone p-n junctions as photoanodes by combing a facile spin-coating process and water bath reaction.This structure strengthens the light harvesting and promotes the charge separation and transport ability.The surface defects states are passivated by coating conformally ultrathin TiO2 onto CuO surface through atomic layer deposition(ALD)technique.Benefiting from the favorable morphology,energy band,and surface treatment,the BiVO4/CuO/TiO2 heterojunction generates an improved photocurrent that is much higher than pure BiVO4.The detailed mechanism investigations indicate that the synergetic optimization of charge separation and injection efficiency in the bulk and surface of photoelectrodes can significantly improve the performance of PEC cells.

Synergistic effect of atomic layer deposition-assisted cocatalyst and crystal facet engineering in SnS2 nanosheet for solar water oxidation

The severe bulk recombination and sluggish oxygen evolution reaction(OER)dynamics of photoanodes severely restrict the application of photoelectrochemical(PEC)devices.To solve these two problems,crystallographic facet orientation and cocatalyst emergence with a high-quality photoanode/cocatalyst interface were realized through an air annealing-assisted strategy to treat atomic layer deposition(ALD)-modified SnSnanosheet arrays.Based on experimental observations and theoretical calculations,the reduced(001)crystal facet of SnSdecreases the recombination of photogenerated carriers in the bulk and improves the carrier separation of the photoanode.Moreover,the unexpectedly formed ZnTiOSfilm decreases the overpotential of the surface OER,reduces interface recombination,and extends the carrier lifetime.These synergistic effects lead to significantly enhanced PEC performance,with a high photocurrent density of 1.97 mA cm^(-2)at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.21 V vs.RHE,which are superior to reported mostly SnS-based photoanodes.

Wrapping BiVO_(4) with chlorophyll for greatly improved photoelectrochemical performance and stability

Dull surface oxygen evolution reaction(OER)dynamics seriously hinders the application of BiVO_(4)(BVO)photoanodes in photoelectron-chemical(PEC)water splitting.In this study,we built an inorganic/organic hybrid photoanode to improve the PEC performance of BVO by covering a multifunctional film.The film contains modified chlorophyll(Chl)organic compounds and Co and Si ions with a gradient distribution.The Co ions present at the interface between BVO and Chl promote the transport of photogenerated holes,and the Si ions on the surface of the photoanode enhance the hydrophilicity of PEC cells.This modified Chl film not only reduces the OER barrier and promotes carrier transfer but also inhibits loss of vanadium and increases the stability of the BVO photoanode.Finally,the modified BVO photoanode exhibits a photocurrent density of 5.1 mA cm^(−2)at 1.23 V_(RHE)(RHE:reversible hydrogen electrode),and the onset potential moves 350 mV negatively in 0.5 mol L^(−1)Na_(2)SO_(4).This article provides a general and simple surface hybrid inorganic/organic solution to improve the catalytic ability of photoanodes.

Recent research progress on operational stability of metal oxide/sulfide photoanodes in photoelectrochemical cells

Photoelectrochemical(PEC)water splitting can directly convert solar energy into hydrogen energy for storage,effectively ending the energy crisis and solving environmental problems.With their modification by many researchers,photoanodes have rapidly improved in PEC performance.Nevertheless,the poor stability of PEC water-splitting devices has not been effectively corrected,seriously hindering their practical application and large-scale commercialization.In this review,we provide a detailed introduction to the photocorrosion mechanism of photoanodes and characterizations of stability,summarizing the current research progress on the stability of metal oxide/sulfide photoanode materials.According to the specificity of each semiconductor,the corrosion mechanism and modification strategy of each photoanode are discussed in detail.Finally,we summarize the deficiencies in the current stability research and propose influencing factors and possible solutions that need to be considered in the photocorrosion research field of photoanodes.This review can provide a reference for the stability research of photoanodes based on metal oxides and sulfides,especially for the design of efficient and stable metal sulfide-based photoanodes.