Carbon-coated molybdenum carbide nanosheets derived from molybdenum disulfide for hydrogen evolution reaction

Abstract The design and synthesis of efficient non-noble metal catalyst is important for the practical application of hydrogen evolution reaction (HER) from water electrolysis. In this study, molybdenum carbides were prepared by a novel synthetic method, which involved the first exfoliation of 2D MoS 2 based on the principle of cold expansion of water below 4 °C and then carburization of exfoliated MoS 2 . In this method, MoS 2 played roles of morphology template and molybdenum source simultaneously. Carbon-coated molybdenum carbide nanosheets were obtained and confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The stripping degree of MoS 2 was found to have an important influence on physical properties and catalytic performance of molybdenum carbides. Interestingly, Mo 2 C nanosheets encapsulated in carbon nanotubes were observed when the MoS 2 with a high peeling degree was used in the preparation. It showed high activity and good durability towards HER in acid solution.