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 mu g h(-1) mg(cat)(-1). 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 *N-2 more thermodynamically favorable than pure 1T'-MoS2. N-15 isotopic labeling experiment confirms that nitrogen in produced ammonia originates from N-2 in the electrolyte.

Automated summary

In this study, 1T'-MoS2/Ti3C2 composite was assembled on the surface of Ti3C2 MXene through a one-step hydrothermal method for nitrogen fixation. The composite exhibited high ammonia yield rate and Faradaic efficiency, as well as good selectivity and stability. It was also found that the 1T'-MoS2/Ti3C2 composite showed better activation and reduction of nitrogen compared to pure MoS2.