Enhancing photoelectrochemical water splitting by combining work function tuning and heterojunction engineering.

ABSTRACT: We herein demonstrate the unusual effectiveness of two strategies in combination to enhance photoelectrochemical water splitting. First, the work function adjustment via molybdenum (Mo) doping significantly reduces the interfacial energy loss and increases the open-circuit photovoltage of bismuth vanadate (BiVO₄) photoelectrochemical cells. Second, the creation and optimization of the heterojunction of boron (B) doping carbon nitride (C₃N₄) and Mo doping BiVO₄ to enforce directional charge transfer, accomplished by work function adjustment via B doping for C₃N₄, substantially boost the charge separation of photo-generated electron-hole pairs at the B-C₃N₄ and Mo-BiVO₄ interface. The synergy between the above efforts have significantly reduced the onset potential, and enhanced charge separation and optical properties of the BiVO₄-based photoanode, culminating in achieving a record applied bias photon-to-current efficiency of 2.67% at 0.54?V vs. the reversible hydrogen electrode. This work sheds light on designing and fabricating the semiconductor structures for the next-generation photoelectrodes.

SUBMITTER: Ye KH 

PROVIDER: S-EPMC6695449 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature