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 nanofibers (NC_PF) with highly dispersed Ni and molybdenum phosphide nanoparticles (Ni-MoP@NC_PF) 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 NC_PF. 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@NC_PF exhibits a CO product selectivity up to 98.95% with a rate of 953.33 μmol g⁻¹h⁻¹ under visible light irradiation, which is 9.37 times faster than that of Ni-free MoP@NC_PF. These findings provide new insights into photocatalytic CO₂ reduction on cost-effective transition metal compounds through combined morphology, composition, and heterointerface engineering. Copyright © 2021 Elsevier B.V. All rights reserved.