Amorphous NiP as cocatalyst for photocatalytic water splitting

As a new photocatalyst, the photocatalytic hydrogen production performance of strontium titanate (SrTiO3, STO) modified by amorphous NiP was studied. The main purpose was to study the effect of amorphous NiP on hydrogen generation of STO under ultraviolet (UV) light irradiation. In this paper, STO catalysts were synthesized by hydrothermal method and the amorphous NiP was modified on the surface of STO by chemical plating method. The photocatalysts were characterized by X-ray diffraction (XRD), ultraviolet visible diffuse reflectance spectroscopy (DRS), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The results show that hydrogen generation rate of STO modified by amorphous NiP (NiP/STO) is much higher than that of STO. Furthermore, the deposition time of chemical plating affects the hydrogen generation performance a lot. The results demonstrate that when the deposition time is 10 s, the hydrogen generation rate reaches almost 3 times higher than the other deposition time. The DRS results indicate that NiP/STO has narrower band gap than STO. Combination of the results of DRS, Mott-schottky (M-S) and XPS, the mechanism of photocatalytic hydrogen generation was obtained. The cause of higher hydrogen generation rate may be ascribed to the different electronic migration path in NiP/STO.