Preparation of a novel Ti/TNAs/PbO2-PVDF-Er2O3 anode by Ti3+ self-doping TNAs and its electrocatalytic performance for hydroquinone degradation

Abstract

A new type of Ti/TNAs/PbO2-PVDF-Er2O3 electrode was prepared in this research via composite electrodeposition method with Ti3+ self-doped modified titanium dioxide nanotubes arrays (TNAs) as the intermediate layer, and co-deposition of PVDF and rare earth Er (Ⅲ) into PbO2, which is expected to be used for efficient degradation of hydroquinone (HQ) wastewater. The research results indicate that the Ti/TNAs/PbO2-PVDF-Er2O3 electrode is composed of more compact β-PbO2, possesses the largest hydrophobicity (97.8°) among the series electrodes. Additionally, the electrode exhibits remarkable electrocatalytic performance with the largest oxygen evolution potential (2.012 V), the largest electrochemical active surface area (ECSA), and the smallest electron transfer resistance (1.054 Ω·cm2). Furthermore, the Ti/TNAs/PbO2-PVDF-Er2O3 electrode is used for the degradation of HQ, and the experiments results reveal that the degradation process is mainly controlled by the indirectly oxidation of ·OH generated on the surface of the electrode, which is presumed to be oxidized to benzoquinone and various fatty acids by ·OH in combination with GC-MS, and finally mineralized to CO2 and H2O. Meanwhile, under the optimum degradation conditions (pH:7, temperature: 30 ℃, Na2SO4: 0.1 M, current density: 50 mA.cm‐2), the degradation rate is up to 94.5%, demonstrating the best electrocatalytic degradation efficiency.