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

A Ni 2+ -containing vanadate, K 2 Ni(VO 3 ) 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 K 2 Ni(VO 3 ) 4 nanoparticles was evaluated by the photodegradation of methylene blue under visible-light irradiation in air. K 2 Ni(VO 3 ) 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 NiO 6 , rich, activated optical centers with tunnel structure for high photocatalytic capacity, and discussed on the basis of the photoluminescence and the decay lifetime.