Chemical Coupled NiCoS/C Nanocages as Efficient Electrocatalyst for Nitrogen Reduction Reaction
Ammonia (NH3) as a significant industrial material as well as the clean energy carrier has been becoming the center of attention. Using electrocatalysis to convert N2 to NH3 at ambient condition is an attracting method among other sustainable methods. However, achieving the high yield of NH3 and high Faraday efficiency (FE) at a low overpotential are still a big challenge in electrocatalytic N2 reduction reaction (NRR). In this work, the strongly chemical coupled NiCoS/C nanocages were firstly used for the conversion of N2 to NH3 in electrocatalytic NRR. Benefiting from the unique structure and strong chemical coupling between C and NiCoS, the NiCoS/C nanocages exhibit superior NRR performance and selectivity in 0.1 M Li2SO4. It can achieve high ammonia production rate of 26.0 μg h-1 mg-1 (2.60 μg h-1 cm-2) and high FE of 12.9 % at 0 V (vs. RHE). Notably, with the potential increasing, the ammonia production rate could reach the highest about 58.5 μg h-1 mg-1 (5.85 μg h-1 cm-2). The density functional theory reveals that the strong chemical coupled effect between NiCoS and C is of great importance in lowering the NRR overpotential, enhancing the electrochemical NRR activity and selectivity. This work provides a new thought for designing the strongly chemical coupled NRR electrocatalysts to realize the high NRR performance at low overpotential.