Efficient utilization of nickel single atoms for CO₂ electroreduction by constructing 3D interconnected nitrogen-doped carbon tube network

The CO₂ electroreduction (CO₂RR) is extensively deemed as a promising route to reach carbon neutralization, while the single-atom catalysts (SACs) are proved to be effective in CO₂RR. However, most SACs cannot further amplify performance due to their powdery feature. Herein, we present numerous isolated nickel single atoms anchored on 3D interconnected N-doped carbon tubes (NiSAs@3D-INCT) network as a self-supported electrode. The NiSAs@ 3D-INCT has truly interconnected and highly ordered vertical and lateral carbon tube-channels, which promote the CO₂ interaction and electrolyte transmission. The NiSAs@3D-INCT exhibits a superior CO₂RR performance with an appreciable CO partial current density of 51.8 mA cm ⁻² at − 0.96 V versus the reversible hydrogen electrode (RHE). X-ray absorption fine structure spectroscopy and theoretical computations reveal the NiSAs are loaded on the 3D-INCT network with Ni-N₄ configuration as highly active sites for CO₂RR. This work will shed a new light on opening up high performance SACs for CO₂RR.