Corrosion behavior of electrodeposited Wo3 thin films

Abstract

In this study, nanostructured tungsten trioxide (WO3) thin films were deposited on Indium tin oxide (ITO)-coated glass substrate using electrochemical deposition (ECD). After deposition, the films were annealed at 450 °C for 2 h in an air atmosphere. X-ray diffraction (XRD) analysis confirmed that the prepared WO3 thin films have crystalline phases. According to the absorption measurements, the optical bandgap of the WO3 film was calculated as Eg 2.80 eV. Based on the scanning electron microscopy (SEM) images, the surface morphology of the thin films was influenced by deposition conditions. Raman spectroscopy analysis was also used to further examine the structure and chemical compositions of the thin films. The nature of the nanostructured WO3 thin films was studied with Electrochemical Impedance Spectroscopy (EIS) and Tafel. Nyquist, open circuit potential and Bode analysis were used to evaluate structural changing and corrosion behavior of the prepared WO3 thin films. With the help of these measurements and analyzes, the parameters such as solution resistance (Rs), polarization resistance (Rpo), a constant phase element (CPE) and a CPE exponent (n) were calculated as 43.43 Ω cm2, 2.67 × 106 Ω cm2, 18.45 × 10−6 Ω−1 s cm−2, 0.958, respectively. Also, the corrosion features of the WO3 thin films were investigated with the help of tafel measurements and the corrosion potential and current values were calculated as −0.583 V and 5.09 × 10−15 A, respectively. It is thought that the prepared thin film might have the potential to be used industrially with these features.