Photocatalytic degradation of Methyl orange on the novel hetero-system La2NiO4/ZnO under solar light

Abstract Complete photocatalytic degradation of methyl orange (MO) was obtained in 60 min on the II-type hetero-system La2NiO4/ZnO, prepared by an impregnation method. The band gap of La2NiO4 and ZnO are 1.87 and 3.10 eV, respectively, with a direct optical transition. The position of the conduction and the valence band in the energy diagram confirms the formation of the II-type hetero-junction, thus facilitating the photo-degradation of MO. The kinetics of MO degradation obeys to the first order apparent reaction with a rate constant of 0.022 min-1. The reutilization of the hetero-system was studied with high removal efficiency after three photocatalysis runs.