Enabling efficient electrocatalytic conversion of N2 to NH3 by Ti3C2 MXene loaded with semi-metallic 1T′-MoS2 nanosheets

Herein, we assemble semi-metallic 1T′ phase MoS2 on the surface Ti3C2 MXene (1T′-MoS2/Ti3C2 composite) by one-step hydrothermal method for nitrogen fixation. 1T′-MoS2/Ti3C2 composites present a high ammonia yield rate of 31.96 µg h−1 mg−1cat. at − 0.95 V vs. RHE and a Faradaic efficiency (FE) of 30.75% at − 0.7 V, which is much better than pure 1T′-MoS2 and pure Ti3C2 MXenes alone. Furthermore, the 1T′-MoS2/Ti3C2 composites exhibit good selectivity and stability with no significant decrease in ammonia yield rate and FE. Density functional theory (DFT) calculations reveal that 1T′-MoS2/Ti3C2 composite makes the activation and further reduction of *N2 more thermodynamically favorable than pure 1T′-MoS2. 15N isotopic labeling experiment confirms that nitrogen in produced ammonia originates from N2 in the electrolyte.