Preparation And Hydrogen Evolution Performances Of Tungsten (Molybdenum)-Based Compounds Activated By High-Energy Ball Milling

With the increasing depletion of traditional fossil energy and the aggravation of environmental pollution problems,the exploitation of efficient and environmentally friendly renewable energy sources is particularly important for the development of human society.As a clean,efficient,and renewable derived energy,hydrogen energy has great application value and development potential.Water electrolysis is an effective technology for hydrogen production;however,due to the high overpotential in the electrolysis hydrogen reaction,a corresponding catalyst is required to reduce the energy consumption of the reaction.Currently,Pt-based noble metals are still the most active and efficient electrocatalysts for hydrogen evolution,but their high cost and scarce reserves make it difficult to achieve large-scale applications.Therefore,the key to scalable industrial hydrogen production is to explore efficient,stable,and inexpensive electrocatalysts.As typical non-noble metal materials,tungsten and molybdenum compounds possess platinum-like catalytic properties and thus are expected to replace noble metal-based catalysts.In this work,tungsten（molybdenum）compounds were studied and activated by high-energy ball milling,and the ball milling process was regulated to prepare electrocatalysts with different activation degrees.The microstructure characterization and electrochemical test of hydrogen evolution were also carried out to systematically study the effects of high-energy ball milling activation on its composition,structure,morphology,and electrocatalytic hydrogen evolution performance.The main research results are as follows:（1）The tungsten disulfide and molybdenum disulfide were activated by high-energy ball milling,and the hydrogen evolution activity of the activated catalysts was greatly improved compared with its counterpart.At a fixed speed of 350 r/min,the hydrogen evolution performance of tungsten disulfide and molybdenum disulfide decreased at 12 h when the ball-milling time was extended;at a constant ball milling time of 12 h,the activity of tungsten disulfide and molybdenum disulfide showed an inflection point at 350 r/min when the ball milling speed was increased,so the optimal ball milling process was 350 r/min-12 h.In 0.5 M H₂SO₄electrolyte,the BM-WS₂-350-12 shows remarkable performance with the overpotential of 245 m V at 10 m A cm^-2,the Tafel slope of 141 m V dec^-1,and the charge transfer resistance R_ctof 129.3Ω.Besides,theη₁₀of BM-Mo S₂-350-12 is 250 m V,with the Tafel slope of 141 m V dec^-1,and the R_ctis 200Ω.（2）For the tungsten carbide and molybdenum carbide activated by the high-energy ball milling,the higher the activation degree,the better the hydrogen evolution performances.At a fixed speed of 350 r/min,the hydrogen evolution performance of tungsten carbide and molybdenum carbide decreased at 24 h when the ball-milling time was prolonged;at a constant ball milling time of 24 h,the hydrogen evolution activity of tungsten carbide and molybdenum carbide showed a decrease at 350r/min when the ball milling speed is increased,so the best ball milling parameter was 350 r/min-24 h.In 0.5 M H₂SO₄electrolyte,theη₁₀of the best sample BM-WC-350-24 is 225 m V,with the Tafel slope of 82 m V dec^-1,and the R_ctis 76Ω.Besides,the BM-Mo₂C-350-12 has anη₁₀of202 m V,with the Tafel slope of 68 m V dec^-1,and the R_ctis 40Ω.