Preparation of 3D PbO2 nanospheres@SnO2 nanowires/Ti Electrode and Its Application in Methyl Orange Degradation

The PbO 2 nanospheres supported on SnO 2 nanowires at Ti substrate (PbO 2 nanospheres@SnO 2 NWs/Ti) electrode was successfully synthesized through hydrothermal method. The structure and morphology of the electrode were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical property was carried out by cyclic voltammogrametry (CV) and UV spectroscopy was used to monitor the changes during the electrochemical degradation process. The results showed that the as-prepared electrode exhibited a three-dimensional (3D) reticulated structure with a large surface area. The average diameter of a single PbO 2 nanosphere is about 300   nm. XRD distinctively identified that the PbO 2 nanospheres was mainly composed of tetragonal-shaped β-PbO 2 crystal. The CV results show that methyl orange (MO) can be oxidized on the electrode surface at the potential of   +1.3   V vs. Ag/AgCl. As much as 92.7% of chemical oxygen demand (COD) was removed in 60   min at 25   °C and pH 5.0 with an applied current density of 15   mA/cm 2 . Proper degradation mechanism was also proposed.