Promoting photoelectrochemical hydrogen production performance by fabrication of Co1-XS decorating BiVO4 photoanode

Abstract Photoelectrochemical (PEC) water splitting is an effective way of converting solar energy into hydrogen (H2) energy. However, the carriers’ transmission and the reaction kinetics of the photoelectrode are dilatory, which will influence the conversion efficiency of solar energy to H2. In this work, a novel of BiVO4/Co1-XS photoanode was successfully fabricated through the successive ionic layer adsorption reaction. The photocurrent density of optimal sample BiVO4/Co1-XS (2.9 mA cm−2 at 1.23 VRHE) has reached up to 5 times that of pure BiVO4, and the applied bias photon to current conversion efficiency increased from 0.04% (BiVO4) to 0.4% (BiVO4/Co1-XS). The superior PEC performance of the BiVO4/Co1-XS photoanode is mainly related to the improved conductivities and reaction kinetics. The charge injection efficiency of BiVO4/Co1-XS grew to about 80%, and the charge separation efficiency was up to 34%, revealing that the decoration of Co1-XS could significantly accelerate the transfer speed of photogenerated carriers from the electrode surface to the electrolyte. This work provided an efficient and simple scheme for improving the PEC performance of photoanode, through reasonable design and research.