Photochemical deposition of palladium nanoflowers on TiO2 nanotubes and their application for the electrocatalytic measurement of iodate ions

Abstract

In the present study, a layer of titanium oxide nanotubes (TiO2NT) was formed by the electrochemical anodization of a titanium sheet (Ti) to produce TiO2NT/Ti. Then, palladium nanoflowers (PdNF) were deposited on the surface of a TiO2NT/Ti electrode by the photocatalytic reduction process. The characterization of TiO2NT/Ti and PdNF/TiO2NT/Ti was performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) techniques. The PdNF/TiO2NT/Ti electrode proved to have catalytic activity for iodate ion (IO3−) reduction. As it was observed, the peak potential of iodate ion reduction at the surface of the PdNF/TiO2NT/Ti electrode shifted toward less negative values than that at the surface of a TiO2NT/Ti electrode. Through an amperometric method, three linear calibration ranges were obtained for iodate ion determination at the modified electrode surface. The detection limit calculated through the same method was 3.4 µM. Finally, the PdNF/TiO2NT/Ti electrode was put to use to determine iodate ions in a commercial salt sample, a nourishment supplement and a drinking water sample. The results were satisfactory.