Fabrication of BiVO4 photoanode catalyzed with bimetallic sulfide nanoparticles for enhanced photoelectrochemical water oxidation

The photoelectrochemical water oxidation ability of BiVO 4 is usually restrained by its low separation efficiency of the photogenerated charge and slow kinetics for water oxidation. Here, FeCoS 2 bimetallic sulfide nanoparticles are successfully coated on BiVO 4 photoanode to address these problems. The photocurrent density of FeCoS 2 /BiVO 4 photoanode is 3.08 times that of BiVO 4 photoanode. Furthermore, the charge separation efficiency can reach 75% and the charge injection efficiency reaches nearly 78%. The onset potential of FeCoS 2 /BiVO 4 shifts 300 mV negatively, while the incident photon-to-electron conversion efficiency value of FeCoS 2 /BiVO 4 is 2.86 folds of BiVO 4 . The enhancement benefits from the loading of FeCoS 2 , which promotes the separation of photogenerated electron and hole, and inhibits the recombination of photogenerated charge and hole. FeCoS 2 /BiVO 4 photoanode shows high photocurrent due to the successful loading of bimetallic sulfide FeCoS 2 . FeCoS 2 /BiVO 4 photoanode has higher light absorption efficiency and active area, which heighten the PEC water oxidation performance. • FeCoS 2 /BiVO 4 reaches a photocurrent of 3.7 mA cm −2 , which is much higher than that of BiVO 4 . • FeCoS 2 /BiVO 4 has high light absorption efficiency and active area, which heighten PEC performance. • FeCoS 2 is superior to FeS and CoS due to its synergistic effect between Fe and Co.