LAUSR

We report the synthesis of Co-doped Mn 3 O 4 nanocubes via galvanic replacement reactions for photo-reduction of CO 2 . Co@Mn 3 O 4 nanocubes can efficiently photo-reduce CO 2 to CO with a remarkable turnover number of 581.8 using [Ru(bpy) 3 ]Cl 2 ·6H 2 O as photosensitizer and triethanolamine as sacrificial agent in acetonitrile and water. The galvanic replaced Co species are homogeneously distributed at the outer surface of Mn 3 O 4 providing the utmost catalytic active sites during CO 2 reduction reactions, which facilitate the separation and migration of photogenerated charge carriers, further benefit the outstanding photocatalytic performance of CO 2 reduction. Density function theory calculation results reveal that the decreasing of conduction band maximum in Co@Mn 3 O 4 is beneficial to the electron attachment from the excited sensitized molecule, which promotes photocatalytic reduction of CO 2 .