Preparation and characterization of a novel blue-TiO_(2)/PbO_(2)-carbon nanotube electrode and its application for degradation of phenol

In this study,we fabricated a blue-TiO_(2)/PbO_(2)-carbon nanotube (CNT) electrode in which blue TiO_(2)nanotube arrays (blue-TNA) served as the substrate for PbO_(2)-CNT eletrodeposition.Scanning electron microscope (SEM) showed compact surface structure of the electrode.The β-PbO_(2)crystal structure was detected by X-ray diffraction (XRD).The distribution of Pb,O,C,and Na elements on the electrode surface have been confirmed by X-ray photoelectron spectroscopy (XPS).Blue-TiO_(2)/PbO_(2)-CNT electrode had higher response current (213.12mA),larger active surface area and lower charge transfer resistance (2.22Ω/cm^(2)) than conventional TiO_(2)/PbO_(2)-CNT electrode.The influences of current density,initial phenol concentration,initial solution pH,and Na2SO_(4)concentration on the electrochemical oxidation of phenol have been analyzed.The results showed that the 100 mg/L phenol could be destroyed completely after 210 min,and chemical oxygen demand (COD) removal rate was 89.3%within 240 min.Additionally,the electrode showed long actual lifetime (5468.80 hr) and low energy consumption (0.08 kWh/gCOD).A phenol degradation mechanism was proposed by analyzing the intermediate products with high-performance liquid chromatography-mass spectrometry (HPLC-MS).Importantly,the blue-TiO_(2)/PbO_(2)-CNT electrode exhibited superior stability and high degradation efficiency after 15 times reuse,demonstrating its promising application potential on phenol-containing wastewater treatment.