Edge-Exposed Molybdenum Disulfide with N-Doped Carbon Hybridization: A Hierarchical Hollow Electrocatalyst for Carbon Dioxide Reduction

Electrochemical CO2 reduction (CO2RR) is a promising technology to produce value-added fuels and weaken the greenhouse effect. Plenty of efforts are devoted to exploring high-efficiency electrocatalysts to tackle the issues that show poor intrinsic activity, low selectivity for target products, and short-lived durability. Herein, density functional theory calculations are firstly utilized to demonstrate guidelines for design principles of electrocatalyst, maximum exposure of catalytic active sites for MoS2 edges, and electron transfer from N-doped carbon (NC) to MoS2 edges. Based on the guidelines, a hierarchical hollow electrocatalyst comprised of edge-exposed 2H MoS2 hybridized with NC for CO2RR is constructed. In situ atomic-scale observation for catalyst growth is performed by using a specialized Si/SiNx nanochip at a continuous temperature-rise period, which reveals the growth mechanism. Abundant exposed edges of MoS2 provide a large quantity of active centers, which leads to a low onset potential of approximate to 40 mV and a remarkable CO production rate of 34.31 mA cm(-2) with 92.68% of Faradaic efficiency at an overpotential of 590 mV. The long-term stability shows negligible degradation for more than 24 h. This work provides fascinating insights into the construction of catalysts for efficient CO2RR.