Multichannel nitrogen-doped carbon fiber confined Fe3C nanoparticles for efficient electroreduction of nitrate†

Electrochemical conversion of nitrate into benign dinitrogen is a promising solution for water purification and environmental remediation. The development of environmentally friendly electrocatalysts possessing excellent catalytic activity and stability has attracted increasing attention. Herein, a 1D hierarchical architecture with uniformly dispersed Fe₃C nanoparticles confined in multichannel nitrogen-doped carbon fibers (Fe₃C/MNCFs) is reported as a highly efficient NO₃RR electrocatalyst. Fe₃C/MNCFs-800 demonstrates a nitrate conversion of 90.9%, an N₂ selectivity of 99.53%, and up to 15 cycles of electrocatalytic stability. The excellent electrocatalytic activity is proposed to be mainly due to the multichannel fibrous architecture beneficial for exposing more active sites and facilitating mass diffusion. Moreover, the strong interaction between active species and fibrous support guarantees the chemical stability and long cycle life. This work provides a reference for the development of high-performance noble-metal-free electrocatalysts for eco-friendly nitrate reduction.