TiO2-NiO p-n nanocomposite with enhanced sonophotocatalytic activity under diffused sunlight

Abstract

TiO2–NiO composites with p–n junction were developed by assembling p-type NiO on n-type TiO2 using ultrasound assisted wet impregnation method. The sonophotocatalytic efficiencies of pure TiO2 and TiO2–NiO composites were evaluated under diffused sunlight using methyl orange (MO) as a model pollutant. The impregnation of NiO nanoparticles on TiO2 considerably enhanced the optical absorption in visible region (500–800 nm) due to the formation of p–n junctions at the interface between TiO2 and NiO. The internal electric field induced by the p–n junction led to effective separation of electron–hole pairs and thereby generating a large amount of reactive species for the degradation of MO. The in..