Enhancement of the electrocatalytic oxidation of dyeing wastewater (reactive brilliant blue KN-R) over the Ce-modified Ti-PbO2 electrode with surface hydrophobicity

Rational hydrophobic anode has been considered as a promising approach for water pollution remediation. However, the construction method of the hydrophobic electrode is limited, such as adding hydrophobic polymer materials. Herein, we address this limitation by developing Ce-modified Ti-PbO2 electrodes with distinctive micro/nanostructures and surface hydrophobicity by the typical electro-deposition process. The Pb ions in the lattice of PbO2 crystals can be substituted by cerium ions and the PbO2 crystal grains were refined when the concentration of cerium ions is low. Specifically, as further increase of the cerium content in plating solution, the CeO2 gradually precipitated on the surface of PbO2 and the PbO2 phase was becoming more and more amorphous. Namely, the pyramid structure converted to surface outshoots with outward oriented-growth, and then evolved gradually to branched projections, until the coral-like architecture was constructed by assembling of small particles. More importantly, the micro/nanostructures and surface hydrophobic PbO2 coatings can significantly enhance generating and utilizing efficiency of hydroxyl radicals, charge transfer rate, and electrochemical active area. The excellent electrochemical performance is mainly attributed to superior catalytic activity arises from synergetic effects between cerium and PbO2 and distinctive micro/nanostructures hydrophobicity surface of Ce-modified Ti-PbO2 electrodes.