Study On The Preparation Of Ru/Transition Metal(Mo,W) Oxide Composite Materials And Its Electrocatalytic Performance

Due to the traditional energy crisis and environmental pollution problems,as a high energy density,clean and pollution-free energy source,hydrogen has attracted great attention.In the existing hydrogen production technology,water electrolysis consisting of cathode electrocatalytic hydrogen evolution reaction(HER)and anode electrocatalytic oxygen evolution reaction(OER)are effective method to generate carbon-free,and high-purity hydrogen.Generally,Pt and RuO2 materials are the benchmark catalysts for HER and OER,respectively.However,the high cost and scarce resources of precious metal catalysts have severely undermined their widespread application.In order to achieve efficient hydrogen production,it is necessary to explore low-cost and high-performance electrocatalysts.Metal/metal oxide composite catalysts have received more and more attention due to their low cost and high catalytic activity.In this thesis,the Ru/transition metal(Mo,W)oxide electrocatalyst was prepared by redox solid phase reaction(SPR).The synergistic effect between metal and metal oxide improves the activity of the composite catalyst.The specific research is as follows:1、The Ru/WO3 hybrid was designed and synthesized by redox SPR.First,the RuO2/WS2 hybrid was synthesized by a two-step hydrothermal method.Then,after the oxidation-reduction reaction of RuO2 and WS2 occurred during the annealing process,Ru nanoparticles(NPs)were successfully loaded onto WO3 nanosheets.Due to the synergistic effect of Ru and WO3,this electrocatalyst exhibits excellent HER electrocatalytic activity under alkaline conditions.At a current density of 10 mA cm-2,it only shows an overpotential of 13 mV,which is comparable to the most advanced the Pt/C electrocatalyst.At a current density of 200 mA cm-2,the overpotential is 341 mV,which is better than that of the Pt/C electrocatalyst.In addition,the catalyst has no abvious deterioration after 5000 cycles,indicating that it has strong stability.It proves that the Ru/WO3 hybrid catalyst has a good HER catalytic activity.2、On the basis of the above work,Ru/RuO2 hybrid NPs were loaded onto MoO2 plane via a redox SPR strategy in order to achieve the high electrocatalytic activity.Due to the restrict transport behavior of atoms in solid state precursor,the redox reaction occurred between the adjacent part of RuO2 and MoS2.The new-formed Ru/RuO2 hybrid NPs and MoO2 plane were tightly combined together and used as electrocatalyst for overall water splitting(OWS).Benefiting from the exposed active sites and optimized electronic structure,the Ru/RuO2-MoO2 catalyst(RRMC-500)exhibited excellent performance with low overpotential values of 18 mV for HER and 260 mV for OER at 10 mA cm-2 in alkaline,respectively.Additionally,a low cell voltage of 1.54 V was needed at 10 mA cm-2 in alkaline.The superior performance indicated its potential application in OWS.