Water splitting reaction on NiO/InVO₄ under visible light irradiation

The photocatalytic activities of InVO₄ and NiO/InVO₄ for water splitting under visible light irradiation were investigated. NiO/InVO₄ photocatalysts pretreated by different process were also investigated. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. The photocatalytic reaction was carried out in a Pyrex glass reactor under visible light irradiation. The XRD patterns indicated that the InVO₄ material was fully crystallized. SEM images showed that after loading NiO, many pin-holes were observed on the surface of the InVO₄ particles. The particle size of the catalyst was about 5 μ m. The band gap of InVO₄ samples was 1.8 eV as estimated from UV-vis spectra. InVO₄ was very active to produce H₂. The NiO/InVO₄ catalyst which was reduced at 500 ^{{ring operator}} C for 2 h and then oxidized at ambient condition for 48 h gave the highest activity, which demonstrated that the pre-treatment process plays a key role in creating high catalytic performance for the NiO/InVO₄ catalyst.