Metallic oxides coated titanium electrode, also called DSA (dimensionally stable anodes), has been developed as insoluble electrode material, which has found extensive applications in the electrochemical engineering, including electro chlorination, waste water treatment, electroplating, electrosynthesis, cathodic protection and so on. Ti based mixed metal oxides coated anodes were rapidly developed in the past decades for their high stability and extreme durability under aggressive operation conditions, especially, large current oxygen evolution conditions such as anodic oxidation, copper deposits of PCB, high speed electroplating, etc. The purpose of this research was the produce Ti/ 70% IrO 2 -30% ZrO 2 electrodes and then the effect of Rhodium oxide with different molar ratios will be discussed on the electrocatalytic activity, electrical conductivity and stability of these kinds. Traditionally, this kind of electrode material is obtained by thermal decomposition of the corresponding metal chloride salt. The substrates were sand-blasted and then degreased in acetone and etched in the boiling 10% (wt) oxalic acid for 2 h to produce gray surface with uniform roughness, finally, washed with distilled water. The Ti substrates were dipped into the solution with different molar ratios and then slowly withdrawn at a rate of 80 mm/min. The thin films were dried at 100?C for 15 min in the oven, and then sintered in the muffle furnace at 450?C for 15 min. This procedure was repeated 7 times with the steps. A final 2 h annealing at 550?C completed the procedure. With increasing Rhodium oxide, It can be seen that etch pits appearance and cracks distribute as network on the surface. Electrolysis test results showed that by increasing the molar percentage of Rhodium oxide, the chemical and electrochemical stability of titanium anode is increased. Electrochemical impedance spectroscopy measurement shows a slight increase in reaction resistance (R ct ) of oxide catalysts for oxygen evolution in the ‘de-active’ region, while a sharp rise in totally physical impedance of the whole anode. CV-profiles, recorded at different anodisation times, showing the voltammetric (i) decreases with increasing t, though the voltammetric profile does not change. EIS investigation has shown that charge transfer resistance at the outer surface area is increased with increasing [RhO x ]. A significant increase in the electrodes active area is observed for compositions corresponding to more than 15 mol% RhO x in admixture with IrO 2 -ZrO 2 . The voltammetric charge decreases with increasing potential scan rate ?.
