高效Ti/PbO_2电极制备及对酸性红G的降解研究

Studies on the preparation of high efficient Ti/PbO_2 electrode and degradation of acid red G

以十二烷基三甲基氯化铵(DTAC)作为添加剂,采用共沉积方式制备新型Ti/PbO_2电极,分别采用扫描电镜、X射线衍射、循环伏安扫描、交流阻抗、X射线光电子能谱及强化寿命等手段对电极性能进行表征,并以酸性红G(ARG)作为目标有机物,考察了添加剂对电极性能的影响.结果表明,经过DTAC改性,电极表层晶相仍为β-PbO_2,但电极表面颗粒细化,比表面积增加,析氧过电位由1.845V提升至1.886V,膜阻抗由102.1?/cm2下降至55.7?/cm2.此外,通过ARG电催化降解及强化寿命测试表明,改性后电极的催化性能及稳定性能均有了很大的提高.其中,对于最优改性电极(PbO_2-DTAC(0.5)),电解60min后ARG的脱色率高达86.8%,强化寿命可达到232.5h,是改性前电极寿命的2倍多(96h).

A novel Ti/PbO2electrode was synthesized through electro-codeposition technology by using dodecyl trimethyl ammonium chloride(DTAC)as an additive.Its characteristics were examined by scanning electron microscopy,X-ray diffraction,cyclic voltammetry,electrochemical impedance spectroscopy,X-ray photoelectron spectroscopy and accelerated life test etc.Electro-catalytic oxidation experiments were carried out to evaluate the effect of DTAC on the electorde's electrochemical activity.Acid red G(ARG,C18H13N3Na2O8S2,CAS number:3734-67-6)was chosen as the model contaminant due to its extensive industrial usage.After DTAC modification,the predominant phase of the electrode was still pureβ-PbO2.However,DTAC could refine the electrode surface leading to a high electrode specific surface area and oxygen evolution potential(OEP,1.886V)and a low electrode film impedance(55.7Ω/cm2).The ARG electrocatalytic degradation and accelerated life tests revealed that the electrocatalytic ability and stability of the modified electrode were much higher compared to that of PbO2electrode.Among these novel electrodes,the PbO2-DTAC(0.5)exhibited the highest electrocatalytic ability for ARG degradation with a decolorization percentage of86.8%within60min.Moreover,its stability was the highest with a long accelerated service life of232.5h,which was more than2times longer than that of PbO2electrode(96h).