New Iron‐Cobalt Oxide Catalysts Promoting BiVO4 Films for Photoelectrochemical Water Splitting. (26th June 2018)

• Record Type: Journal Article
• Authors: Wang, Songcan; He, Tianwei; Yun, Jung‐Ho; Hu, Yuxiang; Xiao, Mu; Du, Aijun; Wang, Lianzhou
• Is Part Of: Advanced functional materials. Volume 28:Number 34(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-26
• Subjects: bismuth vanadate -- iron‐cobalt oxide -- oxygen evolution cocatalyst -- photoanode -- water splitting; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201802685
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Owing to the sluggish kinetics for water oxidation, severe surface charge recombination is a major energy loss that hinders efficient photoelectrochemical (PEC) water splitting. Herein, a simple process is developed for preparing a new type of low‐cost iron‐cobalt oxide (FeCoO x ) as an efficient co‐catalyst to suppress the surface charge recombination on bismuth vanadate (BiVO4 ) photoanodes. The new FeCoO x /BiVO4 photoanode exhibits a high photocurrent density of 4.82 mA cm −2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination, which corresponds to >100% increase compared to that of the pristine BiVO4 photoanode. The photoanode also demonstrates a high charge separation efficiency of ≈90% with excellent stability of over 10 h, indicating the excellent catalytic performance of FeCoO x in the PEC process. Density functional theory calculations and experimental studies reveal that the incorporation of Fe into CoO x generates abundant oxygen vacancies and forms a p‐n heterojunction with BiVO4, which effectively promotes the hole transport/trapping from the BiVO4 photocatalyst and reduces the overpotential for oxygen evolution reaction (OER), resulting in remarkably increased photocurrent densities and durability. This work demonstrates a feasible process for depositing cheap FeCoO x as an excellent OER cocatalyst on photoanodes for PEC water splitting. Abstract : A new iron‐cobalt oxide cocatalyst modified BiVO4 photoanode is designed to promote the sluggish kinetics of water oxidation during photoelectrochemical water splitting, which exhibits a stable high photocurrent density of 4.82 mA cm −2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination for over 10 h.