Indium hydroxide: A highly active and low deactivated catalyst for photoinduced oxidation of benzene

A novel photocatalyst In(OH)3 was synthesized by peptization of a colloidal precipitate under ultrasound radiation. The photocatalyst was characterized by N2 adsorption, XPS, XRD, UV–vis DRS, and FTIR technologies. The photocatalyst sample is highly photoactive and stable for gas-phase removal of benzene under UV irradiation, even in dry O2 atmosphere. Both the conversion of benzene and the mineralization yield are notably accelerated, as compared to the widely used photocatalyst – titania (Degussa P25). In(OH)3 is active even after 30 h of photoreaction. The maximal conversion and mineralization ratio of benzene achieved are 33.4% and 56%, respectively, which is much higher than that obtained with TiO2 (9.5% and 24%). The high activity and durability of the In(OH)3 can be ascribed to the high hole oxidation potential and carbon deposits formed uneasily on the catalyst surface.