Isolated Ni single atoms in nitrogen doped ultrathin porous carbon templated from porous g-C3N4 for high-performance CO2 reduction

Electrochemical reduction of CO2 to value-added products is an effective approach to manage the global carbon balance. However, the lack of effective electrocatalyst for CO2 reduction process is a major obstacle for its development. Currently, constructing atomically dispersed non-precious metal electrocatalysts presents a promising way to build high-performance and cost-effective electrochemical CO2 reduction systems. Herein we demonstrate a novel strategy to realize the anchoring and stabilization of isolated Ni atoms in the nitrogen-doped ultrathin porous carbon nanosheets via a polydopamine-assisted g-C3N4 template method. Benefitting from the abundant atomic Ni sites and ultrahigh specific surface area of porous 2D supports (>1000 m2 g−1), the catalyst exhibits excellent activity for CO2 reduction with particularly high selectivity towards CO, achieving a faradaic efficiency of 96% at −0.86 V (vs. RHE) with a current density of 26.4 mA cm−2 in 0.1 M KHCO3 solution. A high-performance CO2 electroreduction catalyst of isolated Ni atoms supported on nitrogen-doped ultrathin porous carbon nanosheets was fabricated via a polydopamine-assisted g-C3N4 template method. By virtue of the highly active Ni–N4 centres and ultrahigh specific surface area of porous 2D supports, it shows excellent activity for CO2 reduction with particularly high selectivity towards CO. [Display omitted] ●A series of single Ni atom catalysts supported on N doped carbon were fabricated.●Ni contents in single atom catalysts were controllable.●A polydopamine-assisted g-C3N4 template method was employed.●Ni–N4 coordination structure was identified as the active centre.●Excellent activity for CO2 reduction with high selectivity towards CO was achieved.