Preparation Of MoTe₂-based Nano-electrocatalyst For Hydrogen Evolution

As the country attaches importance to hydrogen energy,the development and utilization of new cost-efficient electrocatalysts for the practical production and application of hydrogen has extraordinary significance and value.As a typical transition metal sulfide（TMDs）material,MoTe₂ has unique physical properties that distinguishes from other TMDs members.This thesis takes MoTe₂ as the research object,and studies its role in the electrocatalytic hydrogen production,namely,low-to-medium current density and high current density,through doping,manufacturing defects,and compounding with other substances.It mainly includes the following work:1.Firstly,in order to explore the application of semiconductor 2H-phase MoTe₂for hydrogen production at low and medium current densities,the in-situ transformation method was used to prepare sulfur-doped 2H-phase MoTe₂ containing tellurium vacancies on a nitrogen-doped carbon cloth substrate.When the overpotential is 217m V,the current density over Sulfur-doped Te vacancy 2H-MoTe₂reaches 100 m A cm^-2,and the Tafel slope is 94 m V dec^-1,which proves that the semiconductor 2H-MoTe₂also has high efficiency and stable hydrogen production ability when vacancy and doping are applied.Thus,it is an electrocatalytic candidate for hydrogen production with extraordinary potential.2.Secondly,in order to realize the electrocatalytic hydrogen production at high current density,the design is based on the direct reaction of molybdenum source with tellurium by solid telluride sintering method.The as synthesized 1T’MoTe₂ clusters in-situ enwrapped within nitrogen-doped carbon black.The corresponding tests show that the nanocomposite catalyst can reach a current density of 2000 m A cm^-2.Under optimized reaction conditions,an overpotential of 630 m V can be achieved and the cycle stability can be maintained,which promises a solid foundation for industrial hydrogen production.In view of the fact that the hydrogen production research of MoTe₂ has just started,the research under low-to-medium current densities and high current density is of theoretical and practical significance.This work provides ideas for activating other inert semiconductor nano-catalysts,promoting the research progress of the TMDs family at the level of industrial catalysis.