Co‐Doped Mn ₃ O ₄ Nanocubes via Galvanic Replacement Reactions for Photocatalytic Reduction of CO ₂ with High Turnover Number

The synthesis of Co-doped Mn3 O4 nanocubes was achieved via galvanic replacement reactions for photo-reduction of CO2 . Co@Mn3 O4 nanocubes could efficiently photo-reduce CO2 to CO with a remarkable turnover number of 581.8 using [Ru(bpy)3 ]Cl2 ⋅ 6H2 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 Mn3 O4 , providing catalytic active sites during CO2 reduction reactions, which facilitate the separation and migration of photogenerated charge carriers, further benefiting the outstanding photocatalytic performance of CO2 reduction. Density functional theory calculations revealed that the decreasing of conduction band maximum in Co@Mn3 O4 was beneficial to the electron attachment from the excited sensitized molecule, which promoted photocatalytic reduction of CO2 .