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Enriched Surface Oxygen Vacancies of Photoanodes by Photoetching with Enhanced Charge Separation
Author(s) -
Feng Shijia,
Wang Tuo,
Liu Bin,
Hu Congling,
Li Lulu,
Zhao ZhiJian,
Gong Jinlong
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201913295
Subject(s) - photocurrent , photocathode , electrolyte , oxygen , materials science , electrode , density functional theory , water splitting , hydrogen , oxygen evolution , reversible hydrogen electrode , chemical engineering , chemistry , photochemistry , optoelectronics , electrochemistry , catalysis , photocatalysis , electron , computational chemistry , physics , working electrode , biochemistry , organic chemistry , quantum mechanics , engineering
A facile photoetching approach is described that alleviates the negative effects from bulk defects by confining the oxygen vacancy (O vac ) at the surface of BiVO 4 photoanode, by 10‐minute photoetching. This strategy could induce enriched O vac at the surface of BiVO 4 , which avoids the formation of excessive bulk defects. A mechanism is proposed to explain the enhanced charge separation at the BiVO 4 /electrolyte interface, which is supported by density functional theory (DFT) calculations. The optimized BiVO 4 with enriched surface O vac presents the highest photocurrent among undoped BiVO 4 photoanodes. Upon loading FeOOH/NiOOH cocatalysts, photoetched BiVO 4 photoanode reaches a considerable water oxidation photocurrent of 3.0 mA cm −2 at 0.6 V vs. reversible hydrogen electrode. An unbiased solar‐to‐hydrogen conversion efficiency of 3.5 % is realized by this BiVO 4 photoanode and a Si photocathode under 1 sun illumination.