Modifying the electronic structure of MoS2 via interface engineering to boost intrinsic activity for nitrogen fixation

Electrocatalytic reduction of nitrogen to generate ammonia is a promising process for ammonia production. However, the ammonia yield and selectivity of this process are usually low due to the lack of efficient electrocatalysts. Herein, we prepared a SnS2/MoS2 heterostructure by depositing SnS2 nanoparticles onto MoS2 nanosheets as a catalyst for electrocatalytic nitrogen reduction reaction (eNRR). There is a strong electronic interaction between SnS2 and MoS2 at the heterogeneous interface, which promotes the redistribution of interfacial electrons with directed electron transfer from SnS2 to MoS2, resulting in an increase in the electron density of the Mo sites and an increase in the electrical conductivity of MoS2. The former promotes nitrogen activation and decreases the energy barrier for breaking the N-N triple bond, while the latter accelerates electron transport in the electrocatalytic process and speeds up the eNRR kinetics. The above synergistic effects greatly boost catalytic activity. As a result, a high ammonia yield and Faraday efficiency of 34.3 μgh−1 mg−1 and 13.8% were achieved, respectively.