Enhancements on oxygen vacancy and light absorption of alkaline-etched BiVO4 for photoelectrochemical water oxidation

Tsai Mu Cheng, Kai Jie Chuang, Hsiao Wen Huang, Hung Ming Chen, Yu Min Fan, Sibidou Yougbaré, Lu Yin Lin, Yung Fu Wu

Research output: Contribution to journalArticlepeer-review

Abstract

Designing the favorable morphology with large surface area and abundant oxygen vacancies for BiVO4 can enhance its electron diffusion lengths and improve its photocatalytic ability toward photoelectrochemical water oxidation. The ex-situ alkaline etching process is reported to be facile for enhancing the light absorption and oxygen vacancy of BiVO4, but the systematic study of alkaline etching on the photocatalytic ability of BiVO4 is rare. In this study, alkaline-etched BiVO4 is firstly fabricated using a hydrothermal process with different durations as the photocatalyst of water oxidation. The BiVO4 etched by alkaline for longer durations presents rougher surface, more oxygen vacancies and higher light absorption. The larger carrier densities and the smaller charge-transfer resistances are also achieved for the alkaline etched BiVO4. The largest photocurrent density of 2.38 mA/cm2 is achieved at 1.23 V versus reversible hydrogen electrode in the Na2SO4 electrolyte for BiVO4 etched by alkaline for 45 min, while the pristine BiVO4 electrode only shows a photocurrent density of 0.59 mA/cm2. The photocurrent retention of 81% is also obtained for the alkaline etched BiVO4 electrode after continuous illumination for 6000 s. The results imply the feasibility of applying the alkaline etching process on refining the photoelectrochemical catalytic ability of BiVO4.

Original languageEnglish
Pages (from-to)35561-35571
Number of pages11
JournalInternational Journal of Hydrogen Energy
Volume48
Issue number91
DOIs
Publication statusAccepted/In press - 2023

Keywords

  • Alkaline
  • BiVO
  • Electrodeposition
  • Etching
  • Hydrothermal
  • Water oxidation

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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