Study On Preparation And Application Of Compound Transition Metal Oxide

Composite transition metal oxide has became one of the research hotspots of supercapacitor electrode materials.MnCo₂O₄ nanomaterials have attracted infinite interests for novel structural characteristics.We report a simple hydrothermal method to prepare MnCo₂O₄ materials with different morphologies.The main contents and results are as follows:?1?MnCo₂O₄ nanorods and MnCo₂O₄ microcubes were prepared by aggregation of surfactants?cetyltrimethylammonium bromide and didodecyldimethylammonium bromide?as soft template,followed by calcination.Analysis exhibited that the molar ratios of two kinds of surfactants and the temperature of hydrothermal during preparation played significant roles in affecting the novel morphology of MnCo₂O₄ nanomaterials;?2?The resulting products were analyzed by transmission electron microscopy,field–emission scanning electron microscopy,electron energy loss spectroscopy,X–ray photoelectron spectroscopy,X–ray diffraction,and were characterized by a three–electrode system in KOH(1 mol L^-1)electrolyte solution or Na₂SO₄(1 mol L^-1)electrolyte solution.Results indicated that the length of MnCo₂O₄ nanorods with mesoporous structures that was 2–3?m,the diameter was 100–200 nm,and the mesopore diameter was 10–30 nm.The length of each side of microcubes was 6–15?m,and the mesopore diameter of the microcubes was about 7–12 nm.When the electrolyte solution is 1 mol L^-1 KOH,MnCo₂O₄ microcubes had high specific capacitance(408.33 F g^-1)at a current density of 5 A g^-1,and outstanding long–term cycle stability.These findings indicate that MnCo₂O₄ nanostructured materials show a great promise for a potential nanomaterial as electrodes in supercapacitors.At present,the study of binary metal complex has been more mature,and less research on ternary metal complex.Therefore,we have also studied the ternary metal complex,the main contents and results are as follows:?1?novel zinc–nickel–cobalt ternary oxide nanosheets were successfully synthesized by an easy solvothermal method followed by calcination.By simply controlling the volume ratio of the components in the mixed solvent,the nanosheets were tailored to have different numbers of wrinkles.?2?The prepared zinc–nickel–cobalt ternary oxide nanosheets were characterized by characterization,nanosheets with more wrinkles had a large specific surface area(111.61 m² g^-1),which resulted to improved electrochemical properties.?3?The final products were characterized by a three–electrode system in a KOH(6 mol L^-1)electrolyte solution or Na₂SO₄(1 mol L^-1)electrolyte solution.Based on their novel structures,the nanosheets with more wrinkles displayed good capacitive behavior and excellent specific capacitance retention of 97.18%after charge–discharge cycles?2000 continuous?.Considering their excellent electrochemical performance or simple fabrication,these unique zinc–nickel–cobalt oxide nanosheets show great potential as supercapacitor electrodes for applications in energy storage.