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Abstract
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Cu2O-Cu(OH)2- graphene nanohybrid is successfully deposited on stainless steel (SS) and used as electrode material for supercapacitor application. To prepare nanohybrid film, graphene oxide (GO) film is deposited on SS by electrophoretic deposition (EPD) method from an aqueous suspension of graphene oxide. GO film on SS is converted to graphene (ERGO) film by a rapid, effective and eco-friendly electrochemical reduction method without using reducing reagent. Then, a thin layer of Cu2O-Cu(OH)2 is electrochemically deposited from CuSO4 aqueous solutions at pH = 9 on ERGO/SS. ERGO/SS and Cu2O-Cu(OH)2-ERGO/SS are characterized by scanning electron microscopy, energy dispersive X-ray spectrometry, atomic force microscopic and X-ray diffraction. Cu2O-Cu(OH)2 nanoparticles with diameters around 40 nm are uniformly distributed on the ERGO. Electrochemical performance of as-prepared electrodes is evaluated by cyclic voltammetery, galvanostatic charge/discharge technique and electrochemical impedance spectroscopy in 0.5 M Na2SO4. In three electrode system, the Cu2O-Cu(OH)2-ERGO film shows specific capacitance (Cs) of 425 F g−1 at a current density of 5 A g−1, which is higher than that of ERGO/SS (208 F g−1). Moreover, the symmetric Cu2O-Cu(OH)2-ERGO supercapacitor maintains about 87% of the initial capacitance after 2000 cycles.
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