Persistent luminescence assisted photocatalytic properties of CaAl2O4:(Eu,Nd)/TiO2-xNy and Sr4Al14O25:(Eu,Dy)/TiO2-xNy

The systematic experiments of photocatalytic degradation of NO gas and acetaldehyde were carried out by using novel composites consisting of TiO2-xNy loaded on two types of long afterglow phosphor. CaAl2O4:(Eu,Nd) and Sr4Al14O25:(Eu,Dy). The two kinds of composites were prepared in a sequence of the same procedures, which involved reactions of TiCl3 and hexamethylenetetramine (HMT) mixed solution at 190 degrees C for 2h to precipitate nano-size TiO2-xNy particles, followed by mixing the TiO2-xNy with a micro-size CaAl2O4:(Eu,Nd) or Sr4Al14O25:(Eu,Dy) particles by a facile planetary ball milling to yield CaAl2O4:(Eu,Nd)/TiO2-xNy or Sr4Al14O25:(Eu,Dy)/TiO2-xNy composites. Both composites showed the persistent photocatalytic degradation of NO and acetoaldehyde after turning off the light. CaAl2O4:(Eu,Nd)/TiO2-xNy showed higher persistent NO destruction ability in dark after turning off the light, while Sr4Al14O25:(Eu,Dy)/TiO2-xNy is excellent in CH3CHO removal. The difference in the photocatalytic activity observed for CaAl2O4:(Eu,Nd)/TiO2-xNy and Sr4Al14O25:(Eu,Dy)/TiO2-xNy might be attributed to the difference in the emission property. (c) 2012 Elsevier B.V. All rights reserved.