Sol–gel combustion synthesis of nanocrystalline LaMnO3 powders and photocatalystic properties.

A novel LaMnO₃ photocatalyst with perovskite structure was prepared by sol–gel combustion method. The combustion reaction mechanisms of nanocrystalline LaMnO₃ powders were investigated by thermal analysis, infrared spectra, and X-ray diffraction technique. The results showed that the gels exhibited self-propagating behavior after ignition in air. Nanocrystalline LaMnO₃ powders can be synthesized in one step by using sol–gel combustion synthesis. The photocatalytic activity of the LaMnO₃ powders were evaluated by degradation of methyl orange (MO) in water under UV light irradiation. The results showed that the LaMnO₃ powders exhibit good photocatalytic activities under UV light irradiation. The degradation percentage after 36 h on LaMnO₃ powders was about 76%. [ABSTRACT FROM AUTHOR]