磷钼酸负载碳纳米管复合物的制备及其超级电容性能

以聚多巴胺包覆碳纳米管为载体, 借助聚多巴胺超强的粘附性, 利用简单的溶液浸渍法制备了磷钼酸负载碳纳米管(PMA@CNTs)复合物。通过傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)和电化学测试等对复合物的组成、结构、形态和超级电容性能进行了表征。结果表明: 聚多巴胺可将磷钼酸均匀且牢固地负载在碳纳米管上。在0.5 mol/L的H₂SO₄电解液中, 复合物的最大比容量为511.7 F/g, 最大能量密度可达66.8 Wh/kg, 相应的功率密度为1000 W/kg。经过1000次循环, 比容量无任何衰减。以上研究结果说明PMA@CNTs复合物在电化学储能领域拥有极好的发展前景。

Preparation of Phosphomolybdic Acid Coated Carbon Nanotubes and Its Supercapacitive Properties

The phosphomolybdic acid coated carbon nanotubes (PMA@CNTs) were successfully fabricated by a facile polydopamine-assisted impregnation method, in which polydopamine can form an extraordinary adhesive interlayer to homogeneously adhere PMA on the surfaces of CNTs. The composition, structure, morphology and supercapacitive performances of the resulting PMA@CNTs hybrids were systematically characterized by a range of experimental tools including fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscope(XPS), scanning electron microscope(SEM), transmission electron microscope(TEM), cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD). The PMA can homogeneously loaded onto the surface of the CNTs with the aid of superior adhesion of polydopamine. Here, the performance of the resulting PMA@CNTs hybrids as supercapacitor electrodes was investigated in a three-electrode arrangement using an aqueous electrolyte (0.5 mol/L H₂SO₄). The supercapacitor assembled with the PMA₅₀@CNTs hybrids exhibit the highest specific capacitances (511.7 F/g at 10 mV/s) and maximum energy density of 66.8 Wh/kg at power density of 1000 W/kg, based on the total mass of active materials. In addition, the supercapacitor also has excellent cycling stability retaining>100% of its specific capacitances after 1000 cycles at current density of 5 A/g. These results demonstrate a simple and scalable application of PMA@CNTs hybrids toward electrochemical energy storage.