One-dimensional screw-like MoS2 with oxygen partially replacing sulfur as an electrocatalyst for the N2 reduction reaction

Abstract

• One-dimensional screw-like MoS 2 with oxygen partially replacing sulfur nanosheets are active for NRR. • 1D-MoS 2-x O y nanosheets achieve a large NH 3 yield of 5.56 × 10 -8 mol s −1 cm −2 at −0.35 V vs. RHE. • 1D-MoS 2-x O y nanosheets attain a relatively high Faradaic efficiency of 9.86% at −0.3 V vs. RHE. • 1D-MoS 2-x O y nanosheets show high electrochemical stability. Electrocatalytic nitrogen reduction reaction (NRR) is considered to be an energy-saving method for the production of NH 3 . However, it is still very challenging to achieve a high NH 3 yield and efficiency under ambient conditions. Herein, we for the first time synthesize one-dimensional screw-like MoS 2 with oxygen partially replacing sulfur (1D-MoS 2-x O y ) nanosheets by a one-step solvothermal method as an efficient non-noble metal electrocatalyst for NRR. In a 0.1 M HCl solution, 1D-MoS 2-x O y exhibits excellent NRR performance, with a remarkable average ammonia yield rate of 5.56 × 10 -8 mol s −1 cm −2 at −0.35 V, and a high Faradaic efficiency of 9.86% at −0.3 V. The isotope labeling experiment proves that the generation of NH 3 is completely derived from the feed-in N 2 . Density functional theory calculations show that MoS 2 with oxygen partially replacing sulfur can reduce the Gibbs free energy of the potential determination step (PDS). Besides, the unique screw-like structure can provide more N 2 adsorption sites for NRR. This work proposes a promising strategy for the reasonable design of non-precious metal-based NRR electrocatalysts.