Pseudocubic Phase Tungsten Oxide as a Photocatalyst for Hydrogen Evolution Reaction

Xiandi Zhang, Wei Hao, Chui Shan Tsang, Mengjie Liu, Gyeong S. Hwang, Lawrence Yoon Suk Lee

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)

Abstract

Defect and phase engineering can effectively tune the activity of photocatalysts by altering their band structure and active site configuration. Herein, we report the phase-controlled synthesis of tungsten oxide (WO3) nanoplates via a wet-chemical approach. By adjusting the ratio of trioctylphosphine and trioctylphosphine oxide, oxygen vacancies are induced in WO3 at a relatively low temperature, accompanying the crystal structure transition from monoclinic to orthorhombic or pseudocubic phase. The experimental results and DFT calculations reveal that the increased oxygen vacant sites in WO3 lead to the upshift in both conduction band minimum and valence band maximum. The reformed band structure of reduced WO3 samples (WO3-x) enables the photocatalytic hydrogen evolution without cocatalyst at a maximum steady rate of 340 μmol g-1 h-1 under simulated sunlight. Our work demonstrates a simple and effective strategy of introducing oxygen vacancy to WO3 for band structure tuning, which may be further extended to other metal oxide systems.

Original languageEnglish
Pages (from-to)8792-8800
Number of pages9
JournalACS Applied Energy Materials
Volume2
Issue number12
DOIs
Publication statusPublished - 23 Dec 2019

Keywords

  • band structure engineering
  • oxygen vacancy
  • phase transition
  • photocatalytic hydrogen evolution
  • tungsten oxide

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Electrochemistry
  • Materials Chemistry
  • Electrical and Electronic Engineering

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