Structured BiVO4 Photoanode Fabricated via Sputtering for Large Areas and Enhanced Photoelectrochemical Performance

• Published in: ACS sustainable chemistry & engineering Vol. 8; no. 49; pp. 17923 - 17932
• Main Authors: Ju, Sucheol, Jun, Junho, Son, Soomin, Park, Jaemin, Lim, Hangyu, Kim, Wonjoong, Chae, Dongwoo, Lee, Heon
• Format: Journal Article
• Language: English; Japanese
• Published: American Chemical Society 14.12.2020
• Subjects: patterned FTO; PEC water splitting; BiVO4 sputtering; direct printing; V solution annealing
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.0c05225

Bismuth vanadate (BiVO4) is a promising photoanode material; however, its efficiency significantly changes depending on the atomic ratio of Bi/V, and there is no suitable method for synthesizing large-area photoanodes. In this study, an efficient BiVO4 photoanode was fabricated via sputtering, by manipulating the molar ratio of Bi/V with V solution annealing. V solution annealing not only adjusted the atomic ratio of Bi/V but also increased the number of O vacancies, thereby improving the charge-separation and charge-transport efficiencies. Consequently, the photocurrent density of the sputtered photoanode with V solution annealing (BVO-V) was 1.86 mA/cm2, which is 23 times higher than that of the sputtered photoanode annealed under air conditions (BVO-A, 81.0 μA/cm2). Furthermore, microcone-patterned fluorine-doped SnO2 was fabricated to increase the active area and reduce the high reflectance, owing to the dense deposition because of the sputtering. Thus, the photocurrent density of the MC-BVO was 3.11 mA/cm2, which is approximately 67% higher than that of BVO-V (1.86 mA/cm2).