Yong Peng, Minshu Du, Xingli Zou, Guohua Jia, Shella Permatasari Santoso, Xiang Peng, Wenxin Niu, Mingjian Yuan, Hsien-Yi Hsu
Nickel oxyhydroxide (NiOOH) is regarded as one of the promising cocatalysts to enhance the catalytic performance of photoanodes but suffers from serious interfacial charge-carrier recombination at the photoanode||NiOOH interface. In this work, surface-engineered BiVO4 photoanodes are fabricated by sandwiching an oxygen vacancy (Ovac) interlayer between BiVO4 and NiOOH. The surface Ovac interlayer is introduced on BiVO4 by a chemical reduction treatment using a mild reducing agent, sodium hypophosphite. The induced Ovac can alleviate the interfacial charge-carrier recombination at the BiVO4||NiOOH junction, resulting in efficient charge separation and transfer efficiencies, while an outer NiOOH layer is coated to prevent the Ovac layer from degradation. As a result, the as-prepared NiOOH-P-BiVO4 photoanode exhibits a high photocurrent density of 3.2 mA cm−2 at 1.23 V vs. RHE under the irradiation of 100 mW/cm2 AM 1.5G simulated sunlight, in comparison to those of bare BiVO4, P-BiVO4, and NiOOH-BiVO4 photoanodes (1.1, 2.1 and 2.3 mA cm−2, respectively). In addition to the superior photoactivity, the 5-h amperometric measurements illustrate improved stability of the surface-engineered NiOOH-P-BiVO4 photoanode. Our work showcases the feasibility of combining cocatalysts with Ovac, for improved photoactivity and stability of photoelectrodes. © 2021 Elsevier Inc.
School of Energy and Environment, Department of Materials Science and Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong, China; Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China; School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, China; State Key Laboratory of Advanced Special Steel & School of Materials Science and Engineering, Shanghai University, Shanghai, 200072, China; Curtin Institute of Functional Molecules and Interfaces School of Molecular and Life Sciences, Curtin University GPO Box U1987, Perth, 6845, WA, Australia; Department of Chemical Engineering, Faculty of Engineering, Widya Mandala Surabaya Catholic University, Kalijudan No. 37, Surabaya, 60114, East Java, Indonesia; State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, 130022, Jilin, China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, China; Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430205, China