Synthesis and photocatalytic property of p-n junction YMnO3/SrTiO3 composites

A simple wet chemical route has been used to synthesized the YMnO3, SrTiO3, and YMnO3/SrTiO3 composites. Their crystal structure, surface morphology, optical properties, electrochemical properties and photocatalytic activity were investigated by a series of characterization equipment. From these investigations, it was found that YMnO3 precursor introduced into SrTiO 3 precursor solution improved the phase purity, optical properties, surface morphology and photocatalytic activity of SrTiO3 significantly. Nitrogen physisorption isotherms show that the obtained YMnO3, SrTiO3, and YMnO3/SrTiO3 composites possess high BET specific surface areas (100.21-158.97 m(2) g(-1)) and mesoporous structure (pore size is about 20-25 nm). Photocatalytic experiment results suggest that the YMnO3/SrTiO3 composites exhibits high photocatalytic activities and robust stabilities toward to degradation of methyl red (MR) dye under visible light irradiation. In the p-n junction YMnO3/SrTiO3 composites, the excellent photocatalytic activity may be due to the surface defect promote charge carrier transfer.