Preparation Of MoS₂-based Nanomaterials And Study On Their Electrocatalytic Hydrogen Evolution Performance

Hydrogen has the characteristics of zero emission and high energy density,and is considered to be the most attractive energy source to replace traditional fuels.Electrocatalytic hydrogen production is a sustainable and green approach,which faces great challenge in designing highly active and stable electrocatalysts to replace the state-of-art noble metal platinum catalysts.The near-zero hydrogen adsorption energy of molybdenum disulfide(MoS₂)makes it a promising catalyst and has been widely explored.However,its activity is limited by its semiconductor properties and large inert base plane,making it difficult to meet the practical demands of high performance.In view of the existing obstacles,this paper conducts the following research:MoS₂/Co S₂(0.5)noble metal-free electrocatalysts with higher hydrogen evolution activity than MoS₂were prepared by a facile hydrothermal method.MoS₂and Co S₂are tightly bound together by the shared sulfur atom,which greatly enhances the conductivity of the MoS₂/Co S₂(0.5)nanocomposite,and also increases the active surface area and promotes hydrolysis.These changes resulted in improved catalyst performance.After optimization,the catalyst only needs an overpotential of 62 m V to reach a current density of 10 m A cm^-2and a Tafel slope of 84.6 m V dec^-1.This study provides a facile strategy for the preparation of excellent electrocatalysts.In order to further improve the hydrogen evolution performance of MoS₂-based,we have carried out a careful design on the basis of the above research.We successfully used cobalt carbonate hydroxide(Co CH)nanosheets as substrates and further grown MoS₂to obtain a three-dimensional self-supporting cross-linked(3DSC)structure of Co-MoS₂nano catalysts for hydrogen evolution,which has abundant active centers and fast electron transfer ability.In addition,Co activates the basal-plane sulfur atom in MoS₂to be the HER reactive center effectively.Benefiting from these advantages,3DSC Co-MoS₂electrode integrated on carbon cloth shows that it can drive the current density of 10 and 100 m A cm^-2with only 40 and 119 m V overpotentials,respectively,which is superior to other MoS₂-based hydrogen evolution catalysts reported recently.This study provides a feasible strategy for improving efficient electrocatalysts.