Engineering nickel doped cobalt phosphide as a photocatalyst toward visible-light-driven CO2 reduction

Abstract

Solar-driven photocatalytic CO₂ reduction to clean hydrocarbon fuels offers great potential for mitigating the greenhouse effect and energy crisis. However, achieving high selectivity and efficiency in visible-light-driven CO₂-to-CH₄ conversion remains a major challenge. In this work, a series of nickel-doped cobalt phosphide photocatalysts (NiCoP) with varying doping mass ratios were prepared using ZIF-67 as the precursor. The NiCoP photocatalyst exhibited a unique and regular nanoflower-like spherical structure, making it suitable for visible-light-driven CO₂ reduction. The research demonstrated that, compared to CoP, the synthesized Ni-doped CoP photocatalyst exhibited superior photocatalytic performance in CO₂ reduction, particularly in terms of CH₄ product selectivity. Among the tested catalysts, NiCoP-4 displayed the highest performance, achieving CO and CH₄ production rates of 599.00 and 3458.00 µmol h⁻¹ g⁻¹, respectively. The regular nanoflower-like spherical structure offers enhanced accessibility to active sites and improved charge separation/transfer efficiency, significantly reducing the charge transfer distance. This work provides a theoretical foundation for the development and application of novel nanoflower-like spherical photocatalysts.