Vacancy-rich 1T-MoS2 monolayer confined to MoO3 matrix: An interface-engineered hybrid for efficiently electrocatalytic conversion of nitrogen to ammonia

Electrochemical reduction of nitrogen into ammonia has received attentions as an alternative to the industrial process of Haber-Bosch. Profited from the biomimetic inorganic structure, MoS2 has been proven to be a promising catalyst for electrocatalytic nitrogen reduction reaction (ENRR). However, it suffers from deficient active sites and sluggish kinetics. Herein, a novel ENRR electrocatalyst was synthesized via an interfacial engineering strategy, in which the single-layered 1 T-MoS2 with high density of active sites (S vacancies) is uniformly grown on the supporting MoO3 matrix (denoted as SV-1 T-MoS2@MoO3). Benefiting from the functional S vacancies, well-designed structure and the comparative advantages of metallic 1 T-MoS2 phase, the as-synthesized SV-1 T-MoS2@MoO3 exhibits outstanding electrocatalytic performance with highest NH3 yield rate (116.1 μg h−1 mg−1cat.) and optimized Faradaic efficiency (18.9 %), compared to other previously reported MoS2-based counterparts in acid electrolyte. Density functional theory calculations revealed that the S vacancies can regulate the electronic structure of SV-1 T-MoS2@MoO3 and lead to the antibonding 2π* orbital of N2 molecule moving close to the Fermi level, which greatly promoted the catalytic process towards a more favorable direction for ENRR. The design of SV-1 T-MoS2@MoO3 with hybrid structure in this work provides a reference and enlightenment for better envisagement of efficient nitrogen fixing catalysts.