Self-Supported Porous Carbon Nanofibers Decorated with Single Ni Atoms for Efficient CO₂ Electroreduction

Single-atom catalysts within M-N-C structures are efficient for electrochemical CO₂ reduction. However, most of them are powdered and require a coating process to load on the electrode. Herein, we developed a facile approach to the synthesis of large-scale self-supported porous carbon nanofiber electrodes directly decorated with atomically dispersed nickel active sites using facile electrospinning, where poly(methyl methacrylate) was employed to tune well the distributions of pores located in carbon nanofibers. The above self-supported carbon nanofibers were applied as a gas diffusion electrode to achieve 94.3% CO Faraday efficiency and 170 mA cm^-2 current density, which can be attributed to the effects of rich mesoporous structures favorable for adsorption and mass transfer of CO₂ and single nickel catalysts effectively converting CO₂ to CO. This work provides an efficient strategy to fabricate self-supported electrodes and may accelerate the progress toward industrial applications of single-atom catalysts in the field of CO₂ electroreduction.