Electrochemical behavior and corrosion resistance of IrO2-ZrO2 binary oxide coatings for promoting oxygen evolution in sulfuric acid solution

In this study, we prepared Ti/IrO 2 -ZrO 2 electrodes with different ZrO 2 contents using zirconium-n-butoxide (C 16 H 36 O 4 Zr) and chloroiridic acid (H 2 IrCl 6 ) via a sol-gel route. To explore the effect of ZrO 2 content on the surface properties and electrochemical behavior of electrodes, we performed physical characterizations and electrochemical measurements. The obtained results revealed that the binary oxide coating was composed of rutile IrO 2 , amorphous ZrO 2 , and an IrO 2 -ZrO 2 solid solution. The IrO 2 -ZrO 2 binary oxide coatings exhibited cracked structures with flat regions. A slight incorporation of ZrO 2 promoted the crystallization of the active component IrO 2 . However, the crystallization of IrO 2 was hindered when the added ZrO 2 content was greater than 30at%. The appropriate incorporation of ZrO 2 enhanced the electrocatalytic performance of the pure IrO 2 coating. The Ti/70at%IrO 2 -30at%ZrO 2 electrode, with its large active surface area, improved electrocatalytic activity, long service lifetime, and especially, lower cost, is the most effective for promoting oxygen evolution in sulfuric acid solution.