The performance of BiVO4 for photoelectrocatalytic (PEC) water decomposition is commonly limited by reaction kinetics. In this work, NiS and CoS nanospheres were respectively loaded on BiVO4 thin films (NiS/BiVO4 and CoS/BiVO4 composites) to improve its reaction kinetics for PEC water decomposition. Both physical and chemical properties of these composites were characterized by XRD, SEM, TEM, PL and UV-DRS. The photoelectric properties of the samples were verified by testing LSV, i-t, EIS and IPCE. The formation of the composites can effectively prevent the recombination of carriers and consequently accelerate the separation of electrons and holes. NiS/BiVO4 and CoS/BiVO4 can reach photocurrent of 2.1 mA cm-2 and 2.7 mA cm-2 under light respectively, at 1.23 V vs. RHE, which are 1.75 times and 2.25 times that of BiVO4 (1.2 mA cm-2). The hydrogen production of the NiS/BiVO4 and CoS/BiVO4 photoanodes was 4.7 and 7.3 times higher than that of BiVO4 photoanode, respectively.
Keywords: CoS/BiVO(4); NiS/BiVO(4); Photoelectrochemical water splitting; Visible light.
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