Synthesis, optical properties and photodegradation for methylene blue of Ni-vanadate K2Ni(VO3)4 nanoparticles

Abstract

A Ni2+-containing vanadate, K2Ni(VO3)4 was developed as a new visible-light-driven photocatalyst. The nanoparticles were prepared by the modified Pechini method. The sample was characterized by the measurements such as X-ray powder diffraction, scanning electron microscope, and UV–Vis absorption spectrum. The photocatalytic activity of K2Ni(VO3)4 nanoparticles was evaluated by the photodegradation of methylene blue under visible-light irradiation in air. K2Ni(VO3)4 shows a photocatalytic activity due to the efficient absorption in the UV–Visible-light wavelength region with a narrowed band-gap energy of 2.08 eV and an indirectly allowed electronic transition. These results indicate that this vanadate garnet could be a potential photocatalyst driven by visible light. The effective photocatalytic activity was discussed on the basis of the special structural characteristic such as heavily distorted NiO6, rich, activated optical centers with tunnel structure for high photocatalytic capacity, and discussed on the basis of the photoluminescence and the decay lifetime.