Fabrication and characterization of titanium-based lead dioxide electrode by electrochemical deposition with Ti₄ O₇...

A novelly modified Ti/PbO₂ electrode was synthesized with Ti₄ O₇ particles through electrochemical deposition method (marked as PbO₂ -Ti₄ O₇ ). The properties of the as-prepared electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), hydroxyl radical concentration, accelerated life test, etc. Azophloxine was chosen as the model pollutant for electro-catalytic oxidation to evaluate electrochemical activity of the electrode. The experimental results indicated that Ti₄ O₇ modification could prominently improve the properties of the electrodes, especially, improve the surface morphology, enhance the current response, and reduce the impedance. However, the predominant phases of PbO₂ electrodes were unchanged, which were completely pure β-PbO₂ . During the electrochemical oxidation process, the PbO₂ -Ti₄ O₇ (1.0) electrode showed the best performance on degradation of AR1 (i.e., the highest removal efficiency and the lowest energy consumption), which could be attributed to its high oxygen evolution potential (OEP) and strong capability of HO· generation. Moreover, the accelerated service lifetime of PbO₂ -Ti₄ O₇ (1.0) electrode was 175 hr, 1.65 times longer than that of PbO₂ electrode (105.5 hr). PRACTITIONER POINTS: PbO₂ /Ti₄ O₇ composite anode was fabricated through electrochemical co-deposition. Four concentration gradients of Ti₄ O₇ particle were tested. PbO₂ -Ti₄ O₇ (1.0) showed optimal electrocatalytic ability due to its high OEP and HO· productivity.