Abstract:

Novel Ti/PbO₂ electrodes with polyaniline film (PANI) interlayer were synthesized by electro-deposition technology and characterized by scanning electron microscopy, X-ray diffraction, linear sweep voltammetry and electrochemical impedance spectroscopy. The effect of PANI deposition time on the electrode performance was studied with methyl orange as the probing pollutant and the parameters of degradation experiment were investigated. The performance of Ti/PANI/PbO₂ electrodes for the degradation of rhodamine B and 4-nitrophenol was also studied. The results showed that the PANI deposited on the surface of the electrodes had no effect on the crystal structure and morphology of PbO₂, but can significantly improve the oxygen evolution potential of the electrode. The oxygen potential of Ti/PANI/PbO₂ can reach 3.43V (vs. SCE). When PANI deposition time was 30min, the modified electrode Ti/PANI-30/PbO₂ showed the best electrochemical and electro-catalytic degradation performance. Under the conditions of current density of 30mA/cm², initial pollutant concentration of 50mg/L and Na₂SO₄ concentration of 0.1mol/L, the removal rate of Ti/PANI-30/PbO₂ after 120min of reaction for methyl orange, rhodamine B and 4-nitrophenol was 99.8%, 99.9% and 94.0%, respectively.

Key words: Ti/PANI/PbO₂ electrode, polyaniline film, electro-catalytic oxidation, hydroxyl radical, methyl orange degradation

摘要：

引入导电聚合物聚苯胺膜（PANI，polyaniline）对Ti/PbO₂电极进行改性，采用两步电沉积法成功制备出Ti/PANI/PbO₂电极。通过扫描电镜（SEM）、X射线衍射(XRD)、线性伏安扫描(LSV)和交流阻抗(EIS)对制备的电极进行表征，以甲基橙为目标污染物，探讨了PANI的沉积时间对电极性能的影响，并研究了Ti/PANI/PbO₂电极对罗丹明B和4-硝基苯酚的降解性能。结果表明，PANI的引入未影响活性层PbO₂的晶相结构和形貌特征，但显著提高了电极的析氧电位，Ti/PANI/PbO₂的析氧电位可达3.43V。当PANI聚合时间为30min时，电极Ti/PANI-30/PbO₂的电化学性能和电催化降解效果最佳。在电流密度为30mA/cm²、污染物初始浓度为50mg/L、Na₂SO₄浓度为0.1mol/L的实验条件下，反应120min后，Ti/PANI-30/PbO₂对甲基橙、罗丹明B和4-硝基苯酚的去除率分别为99.8%、99.9%和94.0%。

关键词: Ti/PANI/PbO₂电极, 聚苯胺膜, 电催化氧化, 羟基自由基, 甲基橙降解