Boosting photoelectrochemical water splitting of bismuth vanadate photoanode via novel co-catalysts of amorphous manganese oxide with variable valence states

Can Li; Meihong Chen; Yuhan Xie; Hongqiang Wang; Lichao Jia

doi:10.1016/j.jcis.2023.01.005

Boosting photoelectrochemical water splitting of bismuth vanadate photoanode via novel co-catalysts of amorphous manganese oxide with variable valence states

J Colloid Interface Sci. 2023 Apr 15:636:103-112. doi: 10.1016/j.jcis.2023.01.005. Epub 2023 Jan 4.

Authors

Can Li¹, Meihong Chen¹, Yuhan Xie¹, Hongqiang Wang², Lichao Jia³

Affiliations

¹ Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, 620 West Chang'an Street, Xi'an, Shaanxi 710119,China.
² State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Labortary of Graphene, Xi'an 710072, China. Electronic address: hongqiang.wang@nwpu.edu.cn.
³ Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, 620 West Chang'an Street, Xi'an, Shaanxi 710119,China. Electronic address: lichaojia@snnu.edu.cn.

PMID: 36623364
DOI: 10.1016/j.jcis.2023.01.005

Abstract

Bismuth vanadate (BVO) is a promising photoanode while suffers from sluggish oxygen evolution kinetics. Herein, an ultra-thin manganese oxide (MnO_x) is selected as co-catalyst to modify the surface of BVO photoanode by a facile spray pyrolysis method. The photoelectrochemical measurements demonstrate that surface charge transport efficiency (η_surface) of MnO_x modified BVO photoanode (BVO/MnO_x) is strikingly increased from 6.7 % to 22.3 % at 1.23 V_RHE (reversible hydrogen electrode (V_RHE)). Moreover, the η_surface can be further boosted to 51.3 % at 1.23 V_RHE after applying Ar plasma on the BVO/MnO_x sample_, which is around 7 times higher comparing with that of pristine BVO samples. Additional characterizations reveal that the remarkable PEC performance of the Ar-plasma treated BVO/MnO_x photoanode (BVO/MnO_x/Ar plasma) could be attributed to the increased charge carrier density, extended carrier lifetime and additional exposed Mn³⁺ active sites on the BVO surface. This investigation could provide a new understanding for the design of BVO photoanode with superior PEC performance based on the modification of MnO_x and plasma surface treatment.

Keywords: Ar plasma; Bismuth vanadate; MnO(x) co-catalyst; Photoanode.