Visible-light photocatalysis of lsmo-graphene nanocomposites toward degradation of methyl red

Abstract

La0.7Sr0.3MnO3 (LSMO) nanoparticles were synthesized by a polyacrylamide gel route. LSMO-graphene nanocomposites were fabricated by mixing LSMO nanoparticles and graphene into absolute ethanol solution followed by thermal drying. SEM observation shows that the synthesized LSMO nanoparticles are uniformly and regularly shaped like spheres with an average size of ~24 nm. TEM observation reveals that LSMO nanoparticles are well assembled onto graphene sheets. The photocatalytic activity of prepared samples was evaluated by degrading methyl red (MR) under visible-light irradiation. It is demonstrated that LSMO-graphene nanocomposites exhibit an enhanced photocatalytic activity compared to bare LSMO nanoparticles. This can be explained by the fact that the photogenerated electrons are captured by graphene, leading to an increased availability of holes for the photocatalytic reaction. The direct hole oxidation is suggested to be the main mechanism toward the dye degradation. © 2014 The Japan Institute of Metals and Materials.