Intersperse copper nanoparticles into 3D fibrous silica-supported carbon spheres for electrocatalytic nitrogen reduction

Abstract

The electrocatalysts are critical to the electrocatalytic nitrogen reduction reaction (e-NRR) technique and its development. Herein, through morphological structure modulation, three-dimensional (3D) fibrous silica nanospheres (KCC-1) are firstly fabricated as the supporting scaffold, followed by the coating of nitrogen-doped carbon and interspersing of copper nanoparticles. The resulting carbon spheres (KNC) has very uniform interspersion of copper nanoparticles (Cu-NPs) in the 3D fibrous structure ensuring high accessible active sites for nitrogen molecules; the thin surface carbon layer offering a rich channel for electron transport; and nitrogen dopant allowing efficient electron transfer of copper atoms throng metal-nitrogen covalent bonds. When used as electrocatalysts to e-NRR, KNC exhibits good electrochemical activity, selectivity, and good stability, and can obtain an ammonia yield of approximately 6.67 µg h−1 mgcat−1 and an excellent Faraday efficiency (FE) of 8.1% in 0.1 M sodium sulfate solution at − 0.4 V (vs. RHE).