Basal Plane-Activated Boron-Doped MoS₂ Nanosheets for Efficient Electrochemical Ammonia Synthesis

Under the dual pressure of energy crisis and environmental pollution, ammonia (NH₃ ) is an indispensable chemical product in the global economy. The electrocatalytic synthesis of NH₃ directly from nitrogen and water using renewable electricity has become one of the most attractive and important topics. Basal plane-activated boron-doped MoS₂ nanosheets (B-MoS₂ ) as a non-noble metal catalyst with excellent performance for N₂ electroreduction are synthesized by a facile one-step hydrothermal method. In 0.1 m Na₂ SO₄ solution, MoS₂ nanosheets doped with 300 mg boric acid (B-MoS₂ -300) give rise to a good ammonia yield rate of 75.77 μg h^-1  mg^-1 _cat. at -0.75 V vs. RHE, and an excellent Faradaic efficiency of 40.11 % at -0.60 V vs. RHE. In addition, the B-MoS₂ -300 nanosheets show good selectivity and chemical stability, and no hydrazine (N₂ H₄ ) by-product is generated during the reaction. ¹⁵ N isotopic labeling confirms that nitrogen in produced ammonia originates from N₂ in the electrolyte. On the one hand, the high conductivity of MoS₂ guarantees guarantees a high electron transfer rate from nitrogen to ammonia; on the other hand, the successful incorporation of heteroatom B enlarges the interlayer spacing of MoS₂ , and the B atom can act as an active site for basal plane activation, providing more active sites for the nitrogen reduction reaction (NRR). Density functional theory calculations show that the doping of B activates the base plane of 1T-MoS₂ , which makes the adsorption of N₂ on the base plane easier and promotes the NRR.