Wet-spun Ni, N-codoped macroporous carbon fibers for efficient CO₂ electroreduction and Zn–CO₂ batteries

Developing efficient and cost-effective electrocatalysts for the electrocatalytic CO₂ reduction reaction (eCO₂RR) is highly desirable for carbon neutrality and clean energy. Herein, a self-sacrificing template-assisted wet spinning method is developed to fabricate 3D interconnected Ni, N-codoped macroporous carbon fibers (Ni-NMCF), which possess a uniform distribution of Ni, a large surface area, and abundant accessible active sites. The optimized catalyst, Ni-NMCF-10, shows a high CO faradaic efficiency (FE_CO) over 95% in the potential range from −0.6 to −1.2 V (vs. RHE) and achieves a maximum FE_CO of 99.4% at −0.8 V (vs. RHE). When it is used as a cathode catalyst, the resulting Ni-NMCF-10-based Zn–CO₂ batteries present a maximum power density of 2.4 mW cm⁻² and FE_CO of 98.7%.