Chemical Engineering Journal, Vol.330, 1240-1247, 2017
Predominance of two dimensional (2D) Mn2O3 nanowalls thin film for high performance electrochemical supercapacitors
Well-defined, organized and highly dense Mn2O3 nanowalls are synthesized on nickel (Ni) foam by a facile hydrothermal route and utilize as efficient electro-active electrode for the electrochemical supercapacitors. The crystal structure and quality studies by X-rays diffraction (XRD) and Raman spectroscopy describe the formation of orthorhombic Mn2O3 phases. Uniform and well-organized nanowalls like morphology are grown on the Ni foam in the high aspect ratios with the average wall thickness of 20-30 nm. The highly dense network of Mn2O3 nanowalls in electrochemical system could favor the better electrolyte penetration and supply the ion buffer reservoir to assure the constant supply of electrolyte. From cyclicvoltammetry analysis, the fabricated super-capacitor with Mn2O3 nanowalls electrode accomplishes the excellent capacitance of 480 Fg(-1) at 10 mV s(-1) in 6 M KOH electrolyte. Interestingly, similar specific capacitance of 461 Fg(-1) at 0.5 Ag-1 has obtained from the galvanostat charge-discharge measurements of fabricated super-capacitor with Mn2O3 nanowalls electrode. The grown Mn2O3 nanowalls electrode show the fantabulous cycling stability by maintaining the retention ratio 82% after 5000 cycles. This work paves a new and effective way for the direct preparation of nanowalls-like Mn2O3 thin film to achieve high performance electrochemical supercapacitors.