Double oxygen evolution co-catalysts modified BiVO4 to boost photoelectrochemical water oxidation performance.

Improving the kinetics of oxygen evolution is crucial for enhancing the performance of photoelectrochemical (PEC) water splitting. Herein, this study utilizes a chemical self-growth method to grow NiFe tannic acid complex (NFTA) and Co(OH) 2 on the surface of BiVO 4 photoanode (BiVO 4 /NFTA/Co). As a result, the synergistic effects of NFTA and Co(OH) 2 layers promote the efficiency and stability of BiVO 4 photoanode towards PEC water oxidation. The photocurrent density of the obtained BiVO 4 /NFTA/Co photoanode reaches 4.97 mA cm−2, which is significantly greater than those of BiVO 4 /NFTA (4.36 mA cm−2), BiVO 4 /Co (2.51 mA cm−2), BiVO 4 (1.34 mA cm−2), respectively. Detailed analysis confirms that NFTA could provide an efficient way to hasten the transfer of photo-generated holes on the photoanode surface and diminish the surface charge transfer resistance. In other hand, Co(OH) 2 could be served as a cocatalyst to accelerate charge transfer for efficient oxygen evolution reaction as well as a protective layer to maintain the long-term stability of NFTA on the surface of BiVO 4 during water oxidation. Such double oxygen evolution co-catalysts decoration strategy paves an effective pathway to enhance the PEC water oxidation performance of BiVO 4 photoanode. [Display omitted] • NiFe-tannic acid and Co(OH) 2 co-modified BiVO 4 realizes excellent PEC activities. • The enhanced PEC performance is due to the promoted charge transfer. • BiVO 4 /NFTA/Co photoanode attains 4.97 mA cm−2 at 1.23 V RHE with good durability. [ABSTRACT FROM AUTHOR]