Novel luminescent photocatalytic deNO_x activity of CaAl2O4:(Eu, Nd)/TiO_(2-x)N_y composite

摘要

The systematic experiments of photocatalytic degradation of NO gas were carried out by using novel composites containing TiO_(2-x)N_y loaded on a long afterglow phosphor, CaAl2O4(Eu, Nd). The composites were prepared in a sequence of procedures, which involved reactions of TiCl3 and hexamethylenete-tramine (HMT) mixed solution at 190°C for 2 h to precipitate nano-size TiO_(2-x)N_y particles, followed by mixing the TiO_(2-x)N_y with a micro-size CaAl2O4:(Eu, Nd) particles by a soft planetary ball milling to yield CaAl2O4:(Eu, Nd)/TiO_(2-x)N_y composites. Photocatalytic degradation of NO was monitored both under UV light irradiation and in the dark after turning off the light. The composite displayed excellent photocatalytic activity under UV-light irradiation as well as persistent activity after turning off light. A promising strategy involves coupling of visible light responsive photocatalyst with long afterglow phosphor was established. It is a new concept for the photocatalyst synthesis implying a possibility of a novel persistent active photocatalytic system.