IrO2 coated TiO2 nanopore arrays electrode for SPE HBr electrolysis

IrO2 nanoparticles coated TiO2 nanopore arrays (IrO2/TNPs) electrode has been successfully synthesized by depositing IrO2 on the surface of size-controllable TiO2 nanopore arrays (TNPs), which were fabricated by using anodic oxidation of pure titanium meshes in electrolyte solutions. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), liner sweep voltammetry (LSV), SPE cell polarization curves and electrochemistry impedance spectroscopy (EIS) were adopted to characterize their structures, properties and performances. The IrO2/TNPs electrode has ordered microstructure and more porous surface morphology than that of IrO2/Ti electrode. The electrochemical tests showed that IrO2/TNPs electrode exhibited higher catalytic activity than IrO2/Ti electrode. And the cell voltage can be as low as 1.16 V at 1000 mA cm−2 and 70 °C, which is 90 mV lower than that of the cell with IrO2/Ti electrode (1.25 V). The increase in performance is attributed to the ordered microstructure and porous surface which decrease the interface contact resistance and charge transfer resistance.

► IrO2/TiO2 nanopore arrays (TNPs) electrode is prepared by depositing IrO2 on TNPs.
► The IrO2/TNPs electrode is investigated in SPE HBr electrolysis cell.
► The IrO2/TNPs electrode exhibit higher catalytic activity than IrO2/Ti electrode.
► Preparation conditions significantly affect the IrO2/TNPs electrode performance.