Microwave Synthesis of Unusually-Shaped Crystalline RuO2 Supercapacitor

Abstract

One-step simple temperature-controlled microwave synthesis was applied to prepare nanocrystalline RuO2 dispersion from aqueous RuCl3. RuO2 dispersion was subjected to dynamic light scattering in order to analyze the synthesized particles, whereas structural and morphological properties of the solid phase are investigated by AFM, SEM, EDAX and XRD techniques. The ordered unusual shape of ca. 100-nm native particles, as well as highlyordered prismatic agglomerate sheets are observed. Capacitive properties of RuO2 was investigated by cyclic voltammetry and electrochemical impedance spectroscopy in 1 M H2SO4 and standard three-electrode cell, with ink-type working electrode on glassy carbon substrate A specific capacitances as high as 750 F/g were obtained, which negligibly depend on sweep rate in 5–500 mV/s range. These findings are quite unusual for this kind of material consisted of rather large particles, and makes it excellent candidate for both low and high power applications. The capacitive response appears stable during prolonged charge/discharge cycling.