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Enhanced water splitting on (010) facet-exposed BiVO4 photoanode with improved carrier injection efficiency.

Enhanced water splitting on (010) facet-exposed BiVO4 photoanode with improved carrier injection efficiency.

Authors :
Zhao, Hongru
Wei, Xinkong
Gu, Ruiyin
Xie, Mingzheng
Han, Weihua
Source :
Applied Physics Letters; 10/28/2024, Vol. 125 Issue 18, p1-7, 7p
Publication Year :
2024

Abstract

Transition metal oxide semiconductors, noted for their stability and suitable bandgap, are promising photoanodes for water splitting. Surface engineering is critical to tackle issues like low carrier mobility and charge recombination, stemming from atomic arrangement and Fermi level differences. While exposing dominant crystal facets boosts photocatalytic capability, it can hinder carrier injection into the electrolyte. In this study, BiVO<subscript>4</subscript> films with various facet exposures were synthesized and characterized using scanning electron microscopy and x-ray diffraction to confirm their morphology and crystalline structure. Mott–Schottky analysis was employed to investigate changes in the band structure near the semiconductor–electrolyte interface, revealing that high (010)-BiVO<subscript>4</subscript> facet exposure enhances carrier separation but reduces injection efficiency. The results from photoconductive atomic force microscopy tests demonstrated that enhanced band bending at the semiconductor interface improves hole transfer. Coating the (010)-BiVO<subscript>4</subscript> photoanode with MoS<subscript>2</subscript> and an amorphous ZrO<subscript>2</subscript> interlayer yielded a photocurrent density of 0.6 mA cm<superscript>−2</superscript> at 1.2 V (vs RHE) under AM 1.5 G illumination, tripling the pristine photoanode's performance and nearly tripling water splitting efficiency. Mechanism revealing the improved photoelectrochemical performance is attributed to a greater band bending on the BiVO<subscript>4</subscript> surface, enhancing hole injection dynamics. This work provides a feasible strategy for a deeper understanding of the intrinsic mechanisms of facet engineering and improving the activity of photoanodes. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00036951
Volume :
125
Issue :
18
Database :
Complementary Index
Journal :
Applied Physics Letters
Publication Type :
Academic Journal
Accession number :
180632036
Full Text :
https://doi.org/10.1063/5.0231098