Modulating CoFeO Nanosheets Towards Enhanced CO Photoreduction to Syngas: Effect of Calcination Temperature and Mixed-Valence Multi-Metals.

CoFeO nanosheets were synthesized by a facile coprecipitation and calcination method. The effect of calcination temperature on the crystal texture, morphology and surface areas of CoFeO were fully explored. CoFeO sample calcined at 600 °C (CoFeO -600) showed superior catalytic performance for the reduction of CO under visible light. Compared with the pure Ru(bpy) -sensitized CO reduction system, the CoFeO -added system achieved 19-fold enhancement of CO production (45.7 μmol/h). The mixed valence state and nanosheet-like structure of CoFeO cocatalyst support its ultra-high charge transfer and abundant CO active adsorption sites exposure, which promote the separation of photogenerated charges, and thus improve the photocatalytic CO reduction activity. Carbon source of CO from CO was verified by CO isotopic labelling experiment. Repeated activity experiments confirmed the good stability of CoFeO in the CO photoreduction system. This work would provide prospective insights into developing novel cost-effective, efficient, and durable non-precious metal cocatalysts to improve the efficiency of photocatalytic reduction of CO .