Interface engineering of CoS/MoS2 heterostructure for the electrocatalytic reduction of N2 to NH3

Abstract

As an environmentally friendly and sustainable method for ammonia synthesis, nitrogen reduction reaction (NRR) by electrocatalysis possesses several advantages, including viability under mild conditions, abundant reaction raw materials and low energy consumption, and thus it is supposed to be a promising alternative to the traditional Haber–Bosch process. However, the stable NN bonds in the nitrogen (N₂) and the competing hydrogen evolution reaction (HER) put harsh requirements on catalysts. In this study, the CoS/MoS₂ heterojunction catalyst where CoS nanoparticles are anchored on the MoS₂ nanosheets is reported as a high-efficiency NRR catalyst. The catalysts have high NH₃ yield (23.23 μg h⁻¹ mg_cat.⁻¹), reasonable faradaic efficiency (FE, 12.63%) and long-term electrochemical stability under −0.45 V vs. RHE in 0.1 M Na₂SO₄ solution, whose performance is better than MoS₂ and CoS. The TPV results show rapid interfacial electron transfer and good conductivity of the material, and the DFT calculation reveals that the CoS attached to the (100) plane effectively enhances N₂ adsorption and catalysis performance.