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 °C for 2 h 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.

Even without lamp irradiation, acetaldehyde can be decomposed to produce carbon dioxide efficiently by the fluorescence assisted TiO2−xNy photocatalyst coupled with either CaAl2O4:(Eu,Nd) or Sr4Al14O25:(Eu,Dy) and the composite photocatalyst consisted of Sr4Al14O25:(Eu,Dy) possessed better photocatalytic ability on degradation of acetaldehyde.Figure optionsDownload high-quality image (136 K)Download as PowerPoint slideHighlights
► Sr4Al14O25:(Eu,Dy)/TiO2−xNy as a fluorescence-emitting Photocatalyst.
► Acetaldehyde and continuous flowing NO gas as targets.
► Long afterglow with the wavelength of 490 nm as irradiation source.
► Persistent catalytic ability after turning off light in dark was realized.
► Sr4Al14O25:(Eu,Dy) coupled photocatalyst was superior in the removal of acetaldehyde.