Preparation of ZIF-67/BiVO4 composite photoanode and its enhanced photocathodic protection performance of 316 SS under visible light

• Published in: Journal of alloys and compounds Vol. 961; p. 170926
• Main Authors: Yang, Zhanyuan, Li, Hong, Zhu, Jinke, Li, Weitao, Li, Yanhui, Zhang, Pengfei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.10.2023
• Subjects: BiVO4; In situ growth; Photocathodic protection; UPS; Z-scheme; ZIF-67; In situ growth; UPS; Photocathodic protection; Z-scheme; ZIF-67; BiVO4
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.170926

BiVO4 is a potentially promising photoanode for photocathodic protection (PCP) of metals. Nonetheless, the fast charge recombination and low electron mobility restrict its further utilization. In this work, a cobalt-based metal-organic frameworks (MOFs), zeolitic imidazolate framework-67 (ZIF-67) is incorporated to form the composite ZIF-67/BiVO4 via a facile electrodeposition method. Results show that the ZIF-67/BiVO4 photoanodes present significantly enhanced PCP performance for 316 stainless steel (SS) in comparison with pure BiVO4. The ZIF-67 modified BiVO4 composites with electrodeposition time of 150 s possess the optimal protection performance. The open circuit potential of 316 SS coupled with ZIF-67/BiVO4 could reach − 0.52 V vs. SCE under visible light irradiation in 3.5 wt% NaCl solution without the hole scavengers. The incorporation of ZIF-67 could enhance the visible light absorption ability (λ > 500 nm). In addition, the sensitization of ZIF-67, the increased specific surface area, and the construction of Z-scheme heterojunctions could dramatically promote the separation of electron-hole pairs and retain the strong redox ability of holes or electrons. The photocurrent density of ZIF-67/BiVO4 could reach 99 μA cm−2, which is about 2.5 times that of pure BiVO4. This work shows that porous ZIF-decorated BiVO4 photoelectrodes can provide highly effective PCP for metals, which suggests a promising idea for designing other BiVO4-based photoelectrodes. •ZIF-67 were fabricated on the BiVO4 surface by electrodeposition and in situ growth.•ZIF-67/BiVO4 exhibited enhanced PCP performance for 316 SS under visible light.•The composites have strong absorption in the wavelength range of 500–630 nm.•The carrier separation and transport efficiency has been greatly improved.