摘要：Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of ***,the determination of rate law is rarely *** this purpose,copper oxide(CuO)is selected as a model photocathode in this study,and the photogenerated surface charge density,interfacial charge transfer rate constant and their relation to the water reduction rate(in terms of photocurrent)were investigated by a combination of(photo)electrochemical *** results showed that the charge transfer rate constant is exponential-dependent on the surface charge density,and that the photocurrent equals to the product of the charge transfer rate constant and surface charge *** reaction is first-order in terms of surface charge *** an unconventional rate law contrasts with the reports in *** charge density-dependent rate constant results from the Fermi level pinning(i.e.,Galvani potential is the main driving force for the reaction)due to accumulation of charge in the surface states and/or Frumkin behavior(i.e.,chemical potential is the main driving force).This study,therefore,may be helpful for further investigation on the mechanism of hydrogen evolution over a CuO photocathode and for designing more efficient CuO-based photocatalysts.

摘要：Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental *** vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water ***,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)*** 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)*** 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 *** study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.

摘要：Designing low-cost and high-performance photoelectrodes with improved light harvesting and charge separation rates is significant in photoelectrochemical water ***,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 *** 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 *** as-prepared TiO2/Cu2O/Al/Al2O3 photoelectrodes have an extended absorption range and enhanced carrier separation and *** photocurrent density of 4.52 mA·cm^-2 at 1.23 V *** represents an 1.84-fold improvement over that of TiO2/***,the ultrathin Al2O3 passivation layer spontaneously generated on the surface of Al in air could act as a protective layer to significantly increase its *** 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.

摘要：Solar-driven photoelectrochemical(PEC) water splitting is a promising technology for sustainable hydrogen production, which relies on the development of efficient and stable photoanodes for water oxidation reaction. The thickness and microstructure of semiconductor films are generally crucial to their PEC properties. Herein, three-dimensional(3D) interconnected nanoporous Ta3N5 film photoanodes with controlled thickness were successfully fabricated via galvanostatic anodization and NH3 nitridation. The porous Ta3N5 nanoarchitectures(NAs) of 900 nm in thickness showed the highest PEC performance due to the optimal lightharvesting and charge separation. Compared with the holeinduced photocorrosion, the electrochemical oxidation at high anodic potentials resulted in severer performance degradation of Ta3N5. Although the surface oxide layer on deteriorated Ta3N5 photoanodes could be removed by NH3 re-treatment,the PEC performance was only partially recovered. As an alternative, anchoring a dual-layer Co(OH)x/Co OOH co-catalyst shell on the porous Ta3N5 NAs demonstrated substantially enhanced PEC performance and stability. Overall, this work provides reference to controllably fabricate 3D nanoporous Ta3N5-based photoanodes for efficient and stable PEC water splitting via optimizing the light absorption, hole extraction,charge separation and utilization.