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 5μm. 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∘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.