Sol–gel combustion synthesis and visible-light-driven photocatalytic property of perovskite LaNiO3

A photocatalyst LaNiO3 with perovskite structure was synthesized via a sol–gel combustion technique. The effect of calcination process on the crystallinity, structure and visible-light-driven photocatalytic property of LaNiO3 has been studied. The photocatalysts were characterized by XRD, SEM, BET and UV–vis diffuse reflectance spectrum. The results showed that a single perovskite phase of LaNiO3 was obtained by suitable calcination process. The powder had high surface area. The band-gap of LaNiO3 was 2.26 eV, possessing potential visible-light-induced photocatalytic activity. The photocatalytic activity of the LaNiO3 powders was evaluated by degradation of methyl orange in water under visible light irradiation. The photo-degradation of MO over LaNiO3 was a zero-order reaction and the rate constant k of the best sample in our experiments is 0.1520 (10−2 g L−1 h−1). The degradation percentage after 5 h on the sample was about 74.9%.