Formation of composite Co–Ru oxides/hydroxides for supercapacitors on a nano-structured Co substrate

Svetlana Lichušina; Vitalija Jasulaitienė; Algirdas Selskis; Konstantinas Leinartas

doi:10.6001/chemija.2016.27.4.1

Svetlana Lichušina
Vitalija Jasulaitienė
Algirdas Selskis
Konstantinas Leinartas

DOI: https://doi.org/10.6001/chemija.2016.27.4.1

Keywords: ruthenium oxide, cobalt oxide, pseudo-capacitance

Abstract

A new method of the formation of composite Co–Ru oxides/hydroxides material without a binder for supercapacitors has been proposed. The layers of mixed Co–Ru oxides/hydroxides were formed by the chemical reaction of RuCl3, dissolved in isopropyl alcohol, with a surface of electrochemically deposited nano-structured Co. The surface and bulk composition of synthesized Co–Ru oxides/hydroxides layers were studied by the X-ray photoelectron spectroscopy method. It was determined that the composite Co–Ru layer consisted of mixed oxyruthenium and cobalt hydroxide species of various oxidation states. The layer is characterized by a relatively uniform Co/Ru ratio throughout the bulk. An examination of the surface of formed layers by scanning electron microscopy showed its developed porous morphology. The electrochemical behaviour, the influence of Co substrate on the properties of Co–Ru oxide/hydroxides electrode and stability of the formed layer in 40 g l–1 NaOH solutions were evaluated by the cyclic voltammetry method. The specific capacitance values of ~1230 F g–1 for the composite Co–Ru oxides/hydroxides electrode on the nano-structured Co substrate were determined. Multiple CV cycling of electrodes confirmed good stability of the synthesized Co–Ru oxides/hydroxides layer without a binder.