Microwave-Assisted Synthesis and Characterization of γ-MnO2 for High-Performance Supercapacitors

Abstract Two hydrothermal techniques under microwave irradiation were used to synthesize γ-MnO 2 from 90°C 150°C in 10−30 min. The first technique is based on reducing KMnO 4 with MnSO , and the second one involves liquid-phase oxidation between (NH ) S O 8 . structures morphologies of samples analyzed using X-ray diffraction, scanning electron microscopy, N physisorption measurements. electrochemical properties evaluated through cyclic voltammetry impedance spectroscopy. materials obtained by mainly exhibited nanorods diameters 40–60 nm, showed flower-like microspheres 1−2 µm; each flower was composed nanosheets a thickness 10−20 nm. processing time directly depends size nanorods. sample synthesized at 10 min has highest specific surface area up 59.08 m g −1 mean pore diameter 34.11 Furthermore, this exhibits near-rectangular curves high capacitance 331.3 F 0.1 M Na SO solution 5 mV s scan rate. Graphic abstract