Syntheses Of Molybdenum Polyoxometalate Hybrid Materials And Their Performance Of Electrocatalytic Water Splitting And Supercapacitor

In modern society,the rapid growth of the demand of energy is constantly increasing,which not only leads to the serious shortage of traditional non-renewable resources,but also brings greenhouse effect and environmental pollution and other problems.For these reasons,the researchers commit to the development of efficient,green and clean new energy sources and new energy storage devices.Precious metal electrode materials such as RuO₂are electrode materials with high electrochemical performance,but the high cost and limit reservation limit their applications.The design and development of new electrode materials with low cost,rich storage and excellent performance have become a key point to solve above problems.Polyoxometalates?POMs?have the characteristics of adjustable size,rich various structures,unique redox characteristics and excellent electron transfer ability.While,the POMs often suffer from low electrical conductivity,partial degradation in electrolyte and poor machinability,which obstructs their application as electrode materials.In this paper,POMs based metal-organic framework crystal materials were synthesied,which combined the synergistic effect of both POMs and organic substrates accounting for ideal electrochemical performance.The main contents of the study are as follows:1.Compounds 1 and 2 were synthesized by a hydrothermal synthesis method with different Keggin POM anions,cobalt acetate and L₁organic ligand?3-pyrazinyl-1,2,4-triazole,C₆N₅?.The results of single-crystal diffraction analysis showed that compounds 1 and2 were one-dimensional chain structures,The two compounds are further prepared into electrodes,and the performance of supercapacitors in three-electrode system were studied.The specific capacitance of compounds 1,2 electrode is 182.0 and 12.5F g^-1at 1 A g^-1,respectively.2.Compounds 3 and 4 were synthesized by a hydrothermal synthesis method with different POM anions,acetate copper salt and L₂organic ligand(3-?1H-pyrazol-4-yl?-5-?pyridin-4-yl?-1,2,4triazole,C₁₀N₆H₇).The results of single-crystal diffraction analyses showed that compound 3 was two-dimensional layer structure,and compound 4 was a discrete structure.Futhermore,the bimetallic sulfides Cu₂S-MoS₂@CC?1?and Cu₂S-MoS₂@CC?2?were prepared from compounds 3,4,thiourea and carbon cloth by hydrothermal synthesis at 200?.It shows excellent hydrogen performance in electrolytic aquatic products under acidic conditions.namely,at 0.5 M H₂SO₄electrolyte system,the overpotential is only 237 m V,150 m V and the tafel slope reaches 72m V dec^-1,68m V dec^-1at the current density of 10 m A cm^-2for Cu₂S-Mo S₂@CC?1?and Cu₂S-Mo S₂@CC?2?respectively,showing a highly efficient hydrogen evolution activity.