Preparation, Corrosion Resistance, and Electrochemical Properties of MnO2/TiO2 Coating on Porous Titanium

In this work, MnO2/TiO2 coating on metallic porous titanium was prepared through a hydrothermal-based chemical method, followed by a chemical precipitation reaction of KMnO4 and MnSO4 aqueous solutions. The surface of the MnO2/TiO2/Ti was uniform and compact, with a high load capacity. The corrosion resistance and electrochemical properties of the MnO2/TiO2/Ti coating were investigated in comparison with those of pure Ti and TiO2 coatings. Cyclic voltammetry and constant current charge–discharge measurements showed that the MnO2/TiO2/Ti electrode presented good electrochemical performance. The MnO2/TiO2/Ti electrode had the highest capacitor performance compared to the other electrodes, and the nano-MnO2 coating significantly decreased the corrosion current densities. The nano-MnO2 coating exhibited excellent anti-corrosion properties at room temperature and better capacitance performance compared with pure Ti and TiO2 coatings. After surface modification, TiO2/Ti-coated MnO2 had better electrochemical behavior and significantly improved corrosion resistance than the TiO2/Ti nanocomposites. Its specific capacitance reached 314 F/g, which was 3.5 times that of the TiO2/Ti electrode material.