Amorphous type FeOOH modified defective BiVO4 photoanodes for photoelectrochemical water oxidation

Abstract Herein, a new approach of inducing oxygen vacancy in BiVO4/FeOOH nanostructures is designed, where metal trichalcogenide is introduced. The strategy involves integration of Bi2S3 quantum dots (QDs) in BiVO4/FeOOH to construct defect-rich BiVO4/FeOOH (denoted Vo-BiVO4/FeOOH) as high-performance photoanode for photoelectrochemical water oxidation. Both experimental and theoretical analysis confirm that the excellent PEC performance is due to the introduction of oxygen vacancies and FeOOH cocatalyst, which significantly improves the charge separation. As a result, the obtained Vo-BiVO4/FeOOH photoanode not only demonstrates an optimized Photoelectrochemical (PEC) performance for water oxidation, with photocurrent density of 4.71 mA cm−2 at 1.23 V versus RHE under AM 1.5 G illumination but the interaction of BiVO4 with FeOOH cocatlayst also significantly enhance the stability for Vo-BiVO4/FeOOH without any decrease after 11 h. The oxygen vacancy and FeOOH can effectively enhance the light conversion efficiency, charge transfer efficiencies and charge separation efficiency. This work highlights an effective strategy towards achieving efficient and stable BiVO4 photoanode for sustainable solar energy conversion.