Composite structure and enhanced photocatalytic activity in Mn–Co–Ni–O/LaMnO3 microparticles

Abstract

Abstract A series of Mn–Co–Ni–O/LaMnO3 composite materials were synthesized through the sol-gel method. The structure of these powders changed from the spinel to a spinel–perovskite mixed phase as the content of LaMnO3 increased from 0 to 50%. Meanwhile, some grains of composite material were refined to form many small particles and distributed among the porous microparticles. According to the absorption spectra of composite samples, the strong absorption structures appeared in visible ranges, especially between 400 and 730 nm. The photocatalytic degradation of tetracycline under the visible light irradiation indicated that the percentage of LaMnO3 at 50% exhibited the highest degradation rate (70.2%) in 150 min. Its high photocatalytic activity was mainly due to the large surface area, strong visible light absorption and increased ratio of Mn3+/Mn4+ ions. These new micro-structured photocatalysts were expected to show considerable potential applications in the water treatment.