模板法制备介孔VN纳米电极材料及其电容性能

以十六烷基三甲基溴化铵(CTAB)为模板剂, 通过高温氨解还原V₂O₅前驱体制得了具有丰富介孔的VN纳米材料, 采用XRD与TEM分析观察样品的结构和形貌, 用N2吸附测试样品的比表面积和孔径分布. XRD分析表明, 介孔VN纳米材料属于立方晶系的晶体结构. TEM和N₂吸附测试结果表明, VN纳米材料的颗粒粒径大约为10 nm, 比表面积为88 m²/g, 有比较丰富的2~6 nm的介孔. 在1 mol/L KOH电解液中进行循环伏安和恒流充放电测试研究其电容性能, 结果显示, VN电极同时具有双电层电容性能和氧化–还原反应的准电容性能, 1 mV/s的扫描速率下能获得517 F/g的比电容; 当扫描速率增大到10 mV/s时, 其比电容仍有275 F/g.

Template Synthesis of Mesoporous Nanocrystalline VN Electrode Materials and Its Supercapacitive Behavior

Using hexadecyl trimethyl ammonium bromide (CTAB) as the template, mesoporous VN nanocrystalline was synthesized by NH₃ reduction of precursor V₂O₅. The structure and surface morphology of mesoporous VN were characterized by XRD and TEM. Specific area and pore size distribution were studied by N₂ absorption. The XRD result indicated that VN nanocrystalline belonged to the cubic crystal system. VN nanoparticles were in dimension of about 10 nm. N₂ absorption result indicated that the surface area of VN sample was 88 m²/g, and most pores were distributed in the range of 2–6 nm. The supercapacitive behavior of VN electrode in 1 mol/L KOH electrolyte was studied by cyclic voltammetry (CV) and constant current charge-discharge measurements. The results showed that mesoporous VN electrode had both electrical double-layer capacitive properties and redox pseudocapacitive properties. The specific capacitance was of VN electrode 517 F/g at 1 mV/s scan rate, when the scan rate was up to 10 mV/s, its specific capacitance maintained 275 F/g.