Study On Electrochemical Performance Of Micro-nano Vanadium-based Organic-inorganic Framework Compounds

Metal-organic frameworks?MOFs?have been widely used in supercapacitors and elec-trochemical sensors due to their advantages such as high specific surface area,adjustable pore size,and abundant redox active sites.Electrode material is the most important factor affecting the performance of supercapacitors and electrochemical sensors.It is of great significance to develop a new generation of high-performance electrode materials.Vanadium-based MOFs have the characteristics of simple synthesis,low cost,and many redox active sites.They are expected to be excellent candidates in supercapacitor electrode materials and electrochemical sensor electrode modification materials to detect heavy metal ions.In this paper,four vanadium-based MOFs materials,named MOF?V,Ni?,MOF?V,Cu?,MOF?V,Co?,and MOF?V?,were synthesized by hydrothermal method,their morphology analysis and structural characterization were performed.They have carried out research on its application as electrode materials for supercapacitors and electrode modification materials for the detection of heavy metal ions.The main research contents are as follows:?1?MOF?V,Ni?and MOF?V,Cu?were used as electrode materials for supercapacitorsThe elliptical spherical MOF?V,Ni?and layered MOF?V,Cu?electrode materials were synthesized by hydrothermal method,and their performance was studied as a supercapacitor electrode material.The results show that the specific capacitance of MOF?V,Ni?and MOF?V,Cu?electrode materials can be greatly improved by adding a small amount of K₃[Fe?CN?₆]to the traditional alkaline electrolyte.The composition of the mixed electrolyte in the liquid enhances the performance of MOF?V,Ni?and MOF?V,Cu?electrode materials,the specific capacitances were 1282.31 F/g and 790.57 F/g at 1 A/g,respectively.After 1000 cycles of charge and discharge,it showed high cycle stability,with specific capacitance retention rates of 93.01%and 83.08%,respectively.?2?MOF?V?electrode materials detects Pb²⁺,Cu²⁺and Hg²⁺Fern-like MOF?V?was synthesized by hydrothermal method,it was modified carbon paste electrodes to detect heavy metal ions Pb²⁺,Cu²⁺and Hg²⁺in water through differential pulse voltammetry.The electrochemical sensors exhibit good linearity for detection of three heavy metal ions in the range of 1-10?M and have lower detection limits,2.901×10^-8 mol/L,8.780×10^-8 mol/L,and 6.767×10^-8 mol/L for detection of Pb²⁺,Cu²⁺and Hg²⁺,respectively.?3?MOF?V,Co?and MOF?V,Ni?electrode materials detect Pb²⁺Hexagonal monopyramid MOF?V,Co?and elliptical spherecal MOF?V,Ni?materials were successfully synthesized through hydrothermal method and modified on glassy carbon electrodes and carbon paste electrodes worked as electrode materials,respectively.They were used as electrochemical sensors to detect Pb²⁺.They show good selectivity and good linear detection of Pb²⁺in the range of 1-10?M and 1-20?M,and their limits of detection are2.890×10^-8 mol/L and 2.552×10^-8 mol/L,respectively.