Stable Ti/IrO_2 Anode with Iridium-Titanium Oxide Inter layers for O_2 Evolution

摘要

Ti/IrO_x-TiO_2/IrO_2 and Ti/IrO_2-Ta_2O_5 electrodes were prepared using thermal decomposition procedure, respectively. The microstructure and electrochemical properties of the electrodes were studied with scanning electron microscope (SEM), X-ray diffraction (XRD), potentiodynamic polarization and accelerated life test. Experimental results showed that the Ti/IrO_x-TiO_2/IrO_2 electrode has better electrocatalytic activity for oxygen evolution and higher stability, compared with the Ti/IrO_2-Ta_2O_5 electrode under the same conditions. The high electrocatalytic activity of Ti/IrO_2-TiO_2/IrO_2 electrode could be correlated with a large number of IrO_2 particles on coating surface. The Ti/IrO_x-TiO_2/IrO_2 electrode exhibits a three times longer service life than that of Ti/IrO_2-Ta_2O_5, its superior stability was attributed to the IrO_x-TiO_2 interlayer, which contributes to form a metastable solid solution between IrQ_x and thin titanium oxide layer on titanium substrate during calcination and the improvement of the bonding of IrO_2 layer with the substrate.