“…The photocatalytic CO 2 reduction has attracted more and more attention. Up to now, many semiconductor-based materials, such as ZnO, GaN, ZrO 2 , Bi 2 WO 6 , TiO 2 , and C 3 N 4 , have been developed as functional catalysts for photocatalytic CO 2 reduction, proving that CO 2 can be converted into CO, CH 4 , methanol, and other valued chemicals using H 2 O sacrificial agent [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. After decades of exploration and development, many excellent achievements have been obtained, but the practical application of photocatalytic CO 2 reduction is severely limited by the low activity and the poor stability of the existing catalysts.…”