Electrochemical characterization of PbO₂-TiO₂ composite prepared on stainless steel substrate by cyclic voltammetry method

Abstract

In this study, PbO₂-TiO₂ composite was prepared on stainless steel (SS) substrate by cyclic voltammetry (CV) method from mixed solution containing TiO₂ sol-gel with size from 10 to 50 nm. In the electrochemical deposition, TiO₂ nanoparticle will disperse in the growing PbO₂ coating to create PbO₂-TiO₂ composite. These TiO₂ nanoparticles are delivered from the electrolyte bulk to the eletrode surface by diffusion and migration.The electrochemical properties of SS/PbO₂-TiO₂ electrodes were investigated in 0.5 M H₂SO₄ solution by CV, PP (potentiodynamic polarization), and EIS (electrochemical impedance spectroscopy) methods with and without UV irradiation. The results showed that the exchange current density (iₒ), the value o (iₚ,ₐ and ip,c respectively) depended on the TiO₂ concentration. With a solution containing 2 g/L TiO₂, the value of the redox peaks is the largest and the exchange current density obtained is close the maximum value, indicating that the SS/PbO₂-TiO₂ composite electrode exhibits the best electrochemical activity under this solution condition. Due to the presence of TiO₂ in the composite, the height of the redox peaks and the exchange current density increased sharply under UV light. This demonstrated that the photo-electrochemical activity of the composite is very good, which can be used to remove dyes in wastewater by electrocatalytic oxidation.