Chemical Physics Impact (Jun 2023)
Magnetic and electrochemical application of Ru doped Co3O4 thin films
Abstract
This work describes the preparation of cobalt oxide and Ruthenium doped (x = 0.025, 0.05, 0.075, 0.1) Co3O4 thin films on glass and fluorine-doped tin oxide substrates by spray pyrolysis method. The synthesized samples were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDAX), Fourier Transform Infrared (FTIR), Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), UV-Visible spectroscopy, vibrating sample magnetometer (VSM), Cyclic voltammetry (CV), Linear Sweep Voltammetry (LSV) and Electrochemical Impedance analysis (EIS) to analyze phase purity, surface morphological features, elemental composition, molecular vibrations, optical absorption, magnetic behaviour, super capacitive behaviour and electrical characteristics respectively. The XRD pattern of Ru-doped Co3O4 showed no additional peak compared to Co3O4, with a peak shift observed that confirms the spinel cubic structure of Co3O4. The crystalline size of pure and Ru-doped Co3O4 (0.050) is about 22 nm and 38 nm, respectively. SEM images show pure Co3O4 has smooth and porous morphology, while Ru-doped Co3O4 showed porous, void and cluster formation and increased surface area. The EDAX spectra indicate that the synthesized films are non-contaminated. In Raman spectra, ∼ 480, ∼521, ∼617, and ∼ 689 cm−1 are observed, corresponding to the Eg, F2g, F2g and A1g modes, respectively. From the XPS, binding energy observed at 281.6 eV and 283.6 eV attributed to Ru3d5/2 and Ru3d3/2, respectively. The band gap is about 1.49, 1.28, 1.34, and 1.44 eV for pure Ru-doped Co3O4 thin films. At Ru content x = 0.050, the film exhibits a superparamagnetic nature. The real capacitance of Ru-doped Co3O4 thin film is 158.1 F/cm2 which is slightly increased than Co3O4 thin film. EIS measurement showed a semicircle attributed to oxygen evolution reaction and agrees well with experimental data.
