Synthesis and electrochemical study of ruthenium influenced copper oxide electrodes prepared by self anodization

Self anodization of metal to form their hydroxides and then doped oxides is the versatile technique among the most widely used techniques. Very little work is found in the literature regarding the preparation of Ru doped copper oxide by this method and their use for supercapacitor applications. Here in copper hydroxide thin films were prepared via a self anodization of copper strips in 1 M NaOH bath, followed by Ru doping by the cathodization of these samples in different concentrations of RuCl3 aqueous bath. The typical Ru doped copper hydroxide sample was further annealed at different temperatures to get their oxide forms. All annealed samples were found polycrystalline in nature. SEM supports to the surface morphological change of copper oxide samples with Ru addition. Variation in hydrophilic nature of the samples with annealing temperature was observed. The electrochemical properties of these samples were studied in 1 M aqueous NaOH electrolyte by means of cyclic voltammetry, chronopotentiometry and EIS. All prepared samples exhibited pseudo capacitive behaviour. Sample deposited for 30 min using 0.005 M Ru concentration and there after annealed at 673K shows highest specific capacitance 7700 F/g at 2 mV/s in 1 M NaOH. (C) 2020 Elsevier B.V. All rights reserved.