Effect of hydrothermal temperature on structural, optical and electrochemical properties of α-MnO2 nanostructures for supercapacitor application

One dimensional alpha-MnO2 nanostructures are obtained via a facile hydrothermal method without extra surfactants and additives with different morphologies by varying the hydrothermal temperature. X-ray diffraction (XRD) and Raman spectroscopy confirmed the tetragonal alpha-MnO2 phase. FESEM analysis revealed the morphological variation from nanorods to nanofibres. Electrochemical characterizations like CV, GCD, and EIS were utilized to analyze the supercapacitive properties of the synthesized electrode material in a three-electrode cell using 1 M KNO3 electrolyte. The highest specific capacitance of 218.8 Fg(-1) at 0.5 Ag-1 is obtained for sample M1, and GCD determines excellent cycle stability with 92% retention after 5000 cycles.

Automated summary

One-dimensional alpha-MnO2 nanostructures were synthesized via a facile hydrothermal method with different morphologies obtained by varying the hydrothermal temperature. The synthesized electrode material exhibited excellent supercapacitive properties with the highest specific capacitance of 218.8 Fg(-1) for sample M1, and showed excellent cycle stability with 92% retention after 5000 cycles.