Effect of phase structures of TiO2−xNy on the photocatalytic activity of CaAl2O4:(Eu, Nd)-coupled TiO2−xNy

► CaAl2O4:(Eu, Nd)/TiO2−xNy as a fluorescence-emitting photocatalyst. ► Continuous flowing NO gas as a target. ► Solar light as exciting light. ► Persistent catalytic ability after turning off light in dark was realized. ► Brookite phase TiO2−xNy was superior in this composite photocatalyst.