The Study Of Electro-catalytic Oxidation Of Two Organic Pollutants In Aqueous Solution By Boron-doped Diamond Film Electrode With3D Porous Ti Substrate

The degradation of aqueous nonbiodegradable organics is still a big challenge inthe water treatment field. Electrochemical advanced oxidation technology,characterized by clear process, high efficiency and good controllability, has beenwidely utilized. Boron-doped diamond electrode is one of the best anodes forelectrochemical advanced oxidation technology, since it possesses wideelectrochemical window, low background current and high oxygen evolutionoverpotential. In this study, the performance of3D-Ti/BDD and planar Ti/BDDelectrodes during the electrochemical degradation of two aqueous organic pollutionswas systemically investigated.（1）The surface morphology and crystal structure of3D-Ti/BDD and planarTi/BDD electrodes were studied by SEM and XRD. The results indicate thatuniform, continous and high quality diamond particles have grown on both3D-Ti andplanar Ti substrates. Moreover,3D-Ti/BDD has larger actual surface area due to theporous structure.（2）The cyclic voltammetry measurements of3D-Ti/BDD and planar Ti/BDDelectrodes were performed in potassium ferricyanide/potassium ferrocyanide solution.The results show the3D-Ti/BDD electrode exhibited larger current response than theplanarTi/BDD electrode, which demonstates that the3D-Ti/BDD electrode has more active sites for redox reaction and faster charge-transfer process.Voltammereiccoulometry method was applied to explore the quantity of electric charge and porosityfactor of3D-Ti/BDD and planar Ti/BDD electrodes, which approves above results.（3）3D-Ti/BDD and planar Ti/BDD electrodes were respectively used as anodesin the degradation of DMP(Dimethyl phthalate，DMP). The electrooxidation of DMPon BDD electrodes has been proved as the direct way based on the results of cyclicvoltammetry and linear scanning.The relationship between peak current densityresponse and square root of scan rate showed positive correlation, which means thethe electrooxidation of DMP on BDD electrodes is the first-order reaction. The resultsobtained from HPLC also proved this conclusion.In the degradation of DMP, the3D-Ti/BDD electrode revealed superior performance.（4）3D-Ti/BDD and planar Ti/BDD electrodes were respectively used as anodesin the degradation of Aspirin. Both the production of hydroxyl radical and the removalof Aspirin were in a linear fashion, which proves that the electrooxidation mode ofAspirin on BDD electrodes is an indirect way. In the degradation of Aspirin, the3D-Ti/BDD electrode also revealed superior performance.