Synthesis Of Molybdenum Carbide Nanomaterials As Superior Electrocatalysts For Hydrogen Evolution Reaction

At present,electrolysis of water is regarded as the most ideal way to produce hydrogen.Platinum?Pt?is considered to be the best electrode material for electrochemical hydrogen production.However,the cost and abundance of the catalyst make Pt-catalyzed hydrogen production unsuitable for commercial scale.Therefore,it is imperative to explore low-cost,abundant,highly active and stable non-precious metal electrocatalysts for hydrogen evolution reaction?HER?to replace Pt as a catalyst.In recent years,Earth-abundant transition metal carbides,especially molybdenum carbides?Mo_xC?,are considered as feasible candidates for replacing advanced and expensive Pt-group electrocatalysts.However,there are still challenges in its morphology and catalytic activity.Therefore,molybdenum carbide cathode materials with well-defined and highly active have been widely researched.The research content of this paper mainly includes the following two parts.1.The nickel-molybdenum carbide?Ni-Mo₂C?nanomaterial based on nitrogen-doped carbon nanofiber?N-CNF?was synthesized using tellurium nanowires template-directed hydrothermal carbonization process and characterized by XRD,TEM and XPS.The HER performance of the catalyst with different molar ratios of Ni and Mo was investigated.The results showed that the catalyst with a Ni/Mo molar ratio of 0.046 displayed the best HER activity in acidic electrolyte.It has a small Tafel of 72 mV dec^-11 and a low overpotential of 65 mV at a current density of 10 m A cm^-2,as well as excellent stability.Meanwhile,the catalyst also has well HER acticity in alkaline electrolyte.2.The hybrid of Mo_xC and Ni on the N-doped reduced graphene oxide?Ni-Mo_xC/N-rGO?was rapidly prepared using ultrasonication-assisted and lyophilization method.Moreover,the phase and structure of catalyst was analyzed by TEM,XRD and XPS.In addition,the HER performance was studied.The results showed that the catalyst has excellent HER activity in acidic and alkaline electrolyte.Especially in alkaline electrolyte,the overpotential(at a current density of10 mA cm^-2)of the catalyst is 183 mV and the Tafel is 76 mV dec^-1.In conclusion,electrochemical tests demonstrated that the above catalyst exhibited superior HER activity and high stability.A well foundation is laid for the preparation of non-noble metal electrocatalysts in these works.