IrO 2 -Ta 2 O 5 Anode for Oxygen Evolution with TaO x Interlayer Prepared by Thermal Decomposition in Inert Atmosphere

A novel IrO 2 -Ta 2 O 5 coated titanium anode with TaO x interlayer was prepared using a facile method of thermal decomposition. The interlayer and the composite anodes of Ti/TaO x /IrO 2 -Ta 2 O 5 were characterized with surface analytical techniques of XPS, XRD, SEM and EDS. The electrochemical properties of the composite anodes with different coats of the interlayer were measured using anodic polarization, CV, EIS and accelerated life testing. The results showed that the TaO x interlayer was amorphous consisting of multivalent Ta oxides. The electrocatalytic activity for oxygen evolution reaction and the stability of the composite anodes were improved obviously with adding the TaO x interlayer of appropriate thickness, which can be attributed to the increase of electrochemically active sites and the extra protection for Ti substrate by the non-stoichiometric TaO x interlayer.