Tuning the activity of N-doped carbon for CO2 reduction via in situ encapsulation of nickel nanoparticles into nano-hybrid carbon substrates

Tuning the activity of low-cost carbon materials for electroreduction of CO2 to valuable chemicals and fuels has attracted extensive attention due to its significance in energy and environmental problems, and the main challenge lies in how to tune the electronic structure of such materials using facile strategies. Here, we designed a novel and facile strategy for optimizing nitrogen-doped carbon (N-C) for efficient CO2 reduction reaction (CO2RR) by in situ encapsulation of nickel nanoparticles (NPs) into N-doped carbon nano-hybrid substrates (Ni/N-CHSs). Strikingly, the as-prepared Ni/N-CHS catalyst exhibits excellent performances towards catalyzing CO2 into CO with a high faradaic efficiency of 93.1% at -0.9 V vs. the reversible hydrogen electrode (RHE) and remarkable long-term durability, which is even comparable to those of state-of-the-art CO2RR catalysts. Theoretical calculations indicated that the inclusion of Ni NPs could enhance the activity of N-C for the CO2RR by deeply reducing the activation barriers. This work thus provided an ideal route to rational in situ encapsulation of metal NPs into N-C materials, further tuning the electronic structure and significantly enhancing the CO2RR performance of low-cost carbon materials.