Operando time-resolved diffuse reflection spectroscopy: The origins of photocatalytic water-oxidation activity of bismuth vanadate

Ryo Miyasato, Masazumi Fujiwara, Chiasa Uragami, Haruyuki Sato, Toshihiro Yano, Hideki Hashimoto

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Photocatalytic water splitting has been believed to be a key technology for the construction of a sustainable society based on a renewable energy source. Understanding the exact mechanisms of oxygen evolution by water-splitting reaction, which has been regarded as a bottleneck to realize the water splitting in practical basis, should help us to enhance solar-to-hydrogen energy conversion efficiency. Here, we present a detailed investigation based on two types of bismuth vanadate (BiVO4) crystals. One is a monoclinic scheelite crystal that forms a truncated tetragonal bipyramidal shape (MS), and the other is a tetragonal zircon crystal that forms an octahedral shape (TZ). MS, which has relatively higher photocatalytic activity of water oxidation, rarely adsorbed reduced mediator (Fe2+). Operando time-resolved diffuse reflection spectral measurement demonstrated, for the first time, that the surface holes of MS crystals show extremely high reactivity, while those of TZ crystals show poor reactivity. Our investigation would promote an essential understanding of the photocatalytic reaction mechanism of water oxidation.

Original languageEnglish
Article number112493
JournalJournal of Photochemistry and Photobiology A: Chemistry
Volume395
DOIs
Publication statusPublished - May 15 2020
Externally publishedYes

Keywords

  • Bismuth vanadate
  • Carrier dynamics
  • Photocatalytic water splitting
  • Transient absorption

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Physics and Astronomy(all)

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