Exploring the impact of surface oxygen vacancies on charge carrier dynamics in BiVO4 photoanodes through atmospheric pressure plasma jet post-treatment for efficiency improvement in photoelectrochemical water oxidation

• Published in: Applied catalysis. B, Environmental Vol. 341; p. 123288
• Main Authors: Tsai, Kai-An, Lai, Chien-Chih, Chen, Yu-Hung, Leu, Ing-Chi, Chang, Jui-Cheng, Kuo, Che-Yu, Tseng, Shih-Wen, Li, Yan, Pu, Ying-Chih
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2024
• Subjects: Atmospheric pressure plasma jet; BiVO4; Oxygen vacancy; Photoelectrochemical; Transient absorption spectroscopy; Atmospheric pressure plasma jet; Photoelectrochemical; Transient absorption spectroscopy; BiVO4; Oxygen vacancy
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.123288

We have demonstrated the production of high-density surface oxygen vacancy (ovs) in BiVO4 (BVO) photoanodes through the post-treatment of an atmospheric pressure plasma jet (APPJ). The 3.4-fold enhancement of photocurrent density of BVO photoanodes at 1.23 VRHE for photoelectrochemical (PEC) water oxidation due to 95 % of charge transfer efficiency at the BVO/electrolyte interface. In-situ transient absorption spectroscopy investigations provided insights into the charge carrier dynamics of the APPJ-treated BVO photoanode, revealing that abundant electrons could effectively be trapped in the ovs states to prevent charge carrier recombination. NiOOH/FeOOH oxygen evolution co-catalyst was further decorated on the APPJ-treated BVO photoanode resulted in a remarkable photocurrent density of 3.6 mA/cm2 at 1.23 VRHE, an anodic bias photon-to-current efficiency of 1.4 % at 0.62 VRHE, and a faradaic efficiency over 90 % in PEC water splitting. Our study provides important and novel insights into the surface vacancy engineering of metal oxides for green hydrogen production.
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•Surface oxygen vacancies of BiVO4 photoanodes were produced by APPJ treatment.•Hole transfer efficiency at BiVO4/electrolyte interface achieved 95 % for APPJ-treated BiVO4 photoanodes.•In-situ TAS investigation reveald the long-lived electrons were trapped in surface oxygen vacancies to prevent recombination.•APPJ-treated BiVO4 photoanodes with OEC decoration showed an ABPE of 1.4 % at 0.62 VRHE and a ηf over 90 % in PEC water splitting.