Molybdenum phosphide coupled with highly dispersed nickel confined in porous carbon nanofibers for enhanced photocatalytic CO2 reduction

Photoreduction of CO2 to chemical fuels offers a promising strategy for managing the global carbon balance using renewable solar energy. However, the decisive process of oriented photogenerated electron delivery presents a considerable challenge. The performance of most transition metal compounds, as photocatalysts for CO2 reduction, is largely limited by their inherent stacked structure, poor conductivity, and fast recombination of photogenerated electron-hole pairs. Herein, we report the construction of porous nitrogen-doped carbon nano-fibers (NCPF) with highly dispersed Ni and molybdenum phosphide nanoparticles (Ni-MoP@NCPF) loaded for photocatalytic CO2 reduction. The porous carbon nanofibers with high conductivity and open ends can effectively promote charge/mass transfer and improve CO2 adsorption. The loaded Ni species exist at a highly dispersed state that are stabilized by formation of coordinating Ni-N bonds with N from pyrrolic nitrogen in NCPF. The incorporation of Ni and its electronic coupling with MoP can adjust the band structure of the resultant material and alter the transfer route of the photogenerated carriers. The Ni-MoP@NCPF exhibits a CO product selectivity up to 98.95% with a rate of 953.33 mu mol g(-1)h(-1) under visible light irradiation, which is 9.37 times faster than that of Ni-free MoP@NCPF. These findings provide new insights into photocatalytic CO2 reduction on cost-effective transition metal compounds through combined morphology, composition, and heterointerface engineering.