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Stable Cocatalyst‐Free BiVO 4 Photoanodes with Passivated Surface States for Photocorrosion Inhibition
Author(s) -
Gao RuiTing,
Wang Lei
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202010908
Subject(s) - photocurrent , electrolyte , passivation , photoelectrochemistry , surface states , semiconductor , chemistry , oxygen evolution , chemical engineering , materials science , nanotechnology , electrochemistry , optoelectronics , electrode , surface (topology) , layer (electronics) , geometry , mathematics , engineering
Improving charge transport and reducing bulk/surface recombination can increase the activity and stability of BiVO 4 for water oxidation. Herein we demonstrate that the photoelectrochemical (PEC) performance of BiVO 4 can be significantly improved by potentiostatic photopolarization. The resulting cocatalyst‐free BiVO 4 photoanode exhibited a record‐high photocurrent of 4.60 mA cm −2 at 1.23 V RHE with an outstanding onset potential of 0.23 V RHE in borate buffer without a sacrificial agent under AM 1.5G illumination. The most striking characteristic was a strong “self‐healing” property of the photoanode, with photostability observed over 100 h under intermittent testing. The synergistic effects of the generated oxygen vacancies and the passivated surface states at the semiconductor–electrolyte interface as a result of potentiostatic photopolarization reduced the substantial carrier recombination and enhanced the water oxidation kinetics, further inhibiting photocorrosion.