Electrochemical properties of the IrO2-Ta2O5 coated anodes with Al/Ti and Cu/Ti layered composites substrates

In this paper, the Al/Ti and Cu/Ti layered composite was prepared by the hot-pressing-bonding technique as the basic material of the anodes, and the IrO2-Ta2O5 coatings were thermally deposited on the different kinds of the matrix. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS) were used to study the Al/Ti and Cu/Ti layered composite and IrO2-Ta2O5 coatings. The electrochemical performance of Ti/IrO2-Ta2O5, Al/Ti/IrO2-Ta2O5 and Cu/Ti/IrO2-Ta2O5 composite anodes was studied by linear sweep voltammetry (LSV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that the electrochemical performance of Al/Ti/IrO2-Ta2O5 and Cu/Ti/IrO2-Ta2O5 anodes, compared to the Ti/IrO2-Ta2O5 anode, was effectively improved. Layered composite structure can significantly reduce the resistance and improve the conductivity of the substrate, and the reduction of resistance in electron transfer from electrode to reactants was observed. Because of the resistivity of Cu was the smallest, the resistivity of Cu/Ti layered composite was the lowest (5.1 × 10−8 Ω m), the anodic polarization performance and the electro-catalytic activity of Cu/Ti/IrO2-Ta2O5 anode were the best. The surface electric potential of the Al/Ti/IrO2-Ta2O5 and Cu/Ti/IrO2-Ta2O5 anodes were lower than that of Ti/IrO2-Ta2O5 anode, and the distribution of electric potential on the surface of layered composite anodes was more uniform than that of Ti/IrO2-Ta2O5 anodes.