Photocatalytic CO 2 reduction promoted by a CuCo 2 O 4 cocatalyst with homogeneous and heterogeneous light harvesters

Spinel CuCo2O4 nanoplates were synthesized through a solvothermal method coupled with a calcination treatment in air. The prepared CuCo2O4 samples were fully characterized by diverse physical and chemical techniques including powder X-ray diffraction (XRD), field emission scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and N2 sorption measurement. The CuCo2O4 material was developed as an efficient, low-cost and stable cocatalyst to boost photochemical CO2 conversion with Ru(bpy)32+ as a homogeneous photosensetizer. The catalytic performance of the CuCo2O4 samples was evaluated toward visible-light-driven deoxygenative reduction of CO2 to CO under mild conditions. Various parameters of the reaction system and the synthesis conditions of CuCo2O4 were investigated and optimized to maximize the catalytic performance of CO2 reduction system. The stability and the reusability of the CuCo2O4 cocatalyst were examined. Moreover, the CuCo2O4 cocatalyst was further proved to be highly active to promote CO2 photoreduction catalysed by CdS semiconductor as a heterogeneous light harvester, and markedly reinforced photocatalytic CO2 reduction performance was achieved.