Photocatalytic reduction of CO2 to methanol using Zr(IV)-based MOF composite with g-C3N4 quantum dots under visible light irradiation

Considering the global warming due to the accumulation of excess CO2 in the atmosphere, it is vital to reduce the CO2 emissions by capturing or converting it into value-added chemicals and fuels. Among the known materials, MOFs have great significance in capturing the CO2 and its conversion to energy efficient fuels due to its tuneability, high porosity, large surface area, unique structure, and semiconducting behavior. In the present study, graphitic carbon nitride quantum dots coupled Zr (IV) based MOF composite (g-CNQDs@MOF) has been reported for the photoreduction of CO2 to methanol selectively under visible light irradiation. Graphitic carbon nitride quantum dots (g-CNQDs) in the synthesized Zr-based MOF composite play an important role for photocatalytic CO2 reduction due to its rich photo properties thereby improving the electronic conductance properties of the composite. g-CNQDs in the Zr (IV)-based MOF composite acted as co-catalyst which enhanced the electron-hole separation by elongating the lifetime of photogenerated charge carriers on the surface of MOF composite. These excess electrons accelerated the generation of catalytically active sites on the composite's surface to reduce CO2 selectively into methanol with better selectivity and efficient methanol formation rate.