• C.S. Yaw
  • C. Günnemann
  • D.W. Bahnemann
  • M.N. Chong
Pairing of bismuth vanadate (BiVO4) with vanadium pentoxide (V2O5) forms a Type II heterojunction photoanode, which has been proven to be a high-performance photoanode architecture for efficient photoelectrochemical (PEC) water oxidation. To further support for advanced rational design and improvement of the heterojunction photoanode, it is quintessential to understand the mechanics and properties of photogenerated charge carriers formed. This study aims to probe the dynamics of photogenerated electron-hole pairs formed in pristine photoanode as well as the heterojunction photoanodes using transient absorption spectroscopy (TAS). Relative to the BiVO4/V2O5 structure, modelling and quantification of the decay constant helps in explaining why the V2O5/BiVO4 heterojunction photoanode exhibited a longer lifetime of the photogenerated charge carriers with a lower decay rate constant that leads to a much-improved overall generation of photocurrent density. An oxygen evolving catalyst of nickel oxyhydroxide (NiOOH) was then anchored on the exterior surfaces of the heterojunction photoanode system to further investigate and modify the transfer pathways of the photogenerated charge carriers. Furthermore, the hole- and scavenger-assisted TAS measurements on the BiVO4/V2O5 heterojunction photoanode revealed that the majority of trapped holes species are accumulated within the BiVO4 layer. The findings suggested that the Type II heterojunction formation in V2O5/BiVO4 could effectively reduce its charge recombination process. © 2024 The Authors
Original languageEnglish
Article number177011
JournalJournal of Alloys and Compounds
Volume1010
DOIs
StatePublished - 5 Jan 2025

    Research areas

  • Characterisation, Electron-hole pairs, Heterojunction photoanode, PEC water splitting, Photocatalysis, Decay (organic), Heterojunctions, Transient absorption spectroscopy, Vanadium compounds, Characterization, Dynamic pathways, Electron hole pairs, Photo-anodes, Photoelectrochemical water splitting, Photogenerated charge carriers, Transfer pathway, Transient absorption spectroscopies, Type II heterojunction, Rate constants

ID: 126349934