▎ 摘　　要

Polyaniline/graphene oxide (PANI/GO) co-doped with Zn2+ and Fe3+ was synthesized via a simple and low cost one-step chronoamperometry method on stainless steel (SS) as the substrate. The Fe3+-Zn2+-PANI/GO nanocomposite is characterized using X-ray diffraction as well as Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and field emission scanning electron microscopy. Also, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy are used to study the electrochemical performance of the as-prepared electrode materials. Significantly, the Fe3+-Zn2+-PANI/GO nanocomposite exhibits a specific capacitance of 1140 F g(-1) at a current density of 10 A g(-1), which is far better than PANI (250 F g(-1)), PANI/GO (610 F g(-1)), Fe3+-PANI/GO (744 F g(-1)), and Zn2+-PANI/GO (964 F g(-1)). After 4000 cycles, the fabricated Fe3+-Zn2+-PANI/GO/SS electrode shows 85% capacitance retention at a current density of 5 A g(-1). The resulting good electrochemical performance is owing to the combination of electrical double layer capacitance of GO and pseudocapacitive characteristic of PANI and transition metal ions, which can effectively increase the specific capacitance value and cycling performance of the prepared nanocomposite.