Fabrication of hetero-metal oxide NiCo2V2O8 hollow nanospheres for efficient visible light-driven CO2 photoreduction

Design of highly efficient photocatalysts for CO2 reduction to renewable fuels has gained significant attention for energy sustainability and carbon neutralization. Here, we report the fabrication of hetero-metal oxide NiCo2V2O8 hollow nanospheres through self-templating strategy and anion-exchange reaction. The as-prepared NiCo2V2O8 hollow nanospheres exhibit remarkable CO2 photoreduction, achieving a CO generation rate of 198.65 mu mol g-1 h-1 (9.64 times higher than the undoped Co3V2O8) with 98.8% selectivity under visible light irradiation. Results of experiments and density functional theory (DFT) calculations show that addition of Ni in the hetero-metal oxide and their electronic interaction among d states decrease the bandgap to extend the light absorption, promote CO2 adsorption, and favor the separation of photogenerated charges with inhibited recombination. The in situ FT-IR and Raman spectral results identify the CO2 reduction pathway through COOH* intermediate. This work sheds light on production of solar fuels via an efficient hetero-metal oxide strategy.