Roles of Cr3+ doping and oxygen vacancies in SrTiO3 photocatalysts with high visible light activity for NO removal

► CaAl2O4:(Eu,Nd)/modified SrTiO3 as a fluorescence-emitting Photocatalyst. ► Continuous flowing NO gas as a target. ► Oxygen vacancies-induced SrTiO3 was superior under high-intensity irradiation. ► Cr-doped SrTiO3 emerged as the winner under low-intensity irradiation.