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

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). [Display omitted] •3D fibrous silica-supported carbon sphere is used to intersperse copper NPs.•Accessible open 3D fibrous structure ensures the exposure of active copper.•Surface carbons and nitrogen dopants promote the electron transfer.•The composite exhibits good activity, selectivity, and good stability for e-NRR.