Core-shell Ni/NiO grafted cobalt (II) complex: An efficient inorganic nanocomposite for photocatalytic reduction of CO2 under visible light irradiation

The present paper describes the first successful synthesis of an inorganic nanocomposite by grafting of cobalt (II) phthalocyanine (CoPc) on the core-shell Ni/NiO (NNO) semiconductor for the photocatalytic reduction of CO2 to methanol under visible illumination using triethylamine as a sacrificial donor. The synthesised photocatalyst exhibited a remarkable enhancement in the yield of methanol as compared to the semiconductor Ni/NiO and CoPc for CO2 reduction under identical conditions. The maximum yield of methanol was found to be 3641.2 mu mol/g with the conversion rate of 151.7 mu mol g(-1) h(-1) which was much higher than that observed with CoPc and semiconductor alone under identical experimental conditions. Furthermore, the synthesised nanocomposite showed superior activity as compared to the previously reported organic semiconductor bound cobalt complex photocatalyst. The composite photocatalyst was found to be highly stable which showed consistent recyclability for four runs without any significant loss in activity.