镍掺杂四氧化三钴纳米线阵列的制备及其超级电容特性

采用直流电化学沉积与高温氧化相结合的合成方法, 在氧化铝模板的辅助下, 成功制备了一种新颖的Ni掺杂的Co₃O₄纳米线阵列, 利用X射线衍射仪、扫描电镜和高分辨透射电镜等对所制备的纳米线阵列的物相和形貌进行了表征, 结果表明：所制备的Ni掺杂Co₃O₄纳米线形貌和尺寸均匀、垂直于基底排列, 纳米线的平均直径约为80 nm, 长度约为1.4 μm, 整个纳米线由纳米颗粒堆积而成, 其中Co : Ni的比例约为20 : 1。利用循环伏安和恒流充放电技术在2 mol/L的KOH电解液中对材料的电化学性能进行了测试, 结果显示所制备的纳米线阵列具有优异的电化学电容特性, 当电流密度为10 mA/cm²时, 纳米线阵列的面积比电容为173 mF/cm², 经过1000次充放电后, 比电容值仍能保持最初值的98%, 表现出良好的循环稳定性。优异的性能可归因于材料的比表面积较大以及镍掺杂后材料导电特性的提高。

Synthesis and Supercapacitor Property of Ni-doped Co3O4 Nanowire Array

The novel Ni-doped Co₃O₄ nanowire array was synthesized successfully by electrochemical deposition with the aid of anodic aluminum oxide (AAO) template, followed by oxidation at high temperature. The phase composition and morphology were characterized by X-ray diffraction, scanning electron microscope and high resolution transmission electron microscope. The results show that as-prepared Ni-doped Co₃O₄ nanowire array perpendicular to the substrate displays highly uniform shape and size, with an average diameter of 80 nm and length of 1.4 μm. The nanowire with coarse surface is composed of small crystalline nanoparticles. Average atom ratio of Co to Ni in the nanowire is 20 : 1. Electrochemical characterization was performed using cyclic voltammetry and galvanostatic charge-discharge in a 2 mol/L KOH aqueous solution electrolyte. The test results indicate that the Ni-doped Co₃O₄ nanowire array exhibits a specific capacitance of 173 mF/cm² at current density of 10 mA/cm², and a good cycling stability with 98% capacity retention over 1000 cycles. Excellent electrochemical performance can be attributed to the large specific surface area and the enhanced conductivity achieved by incorporating of Ni.