电化学阴极活化掺硼金刚石膜电极  

Activation of boron-doped diamond electrodes by electrochemically cathodic polarization

作　　者：蒋盈盈[1] 毛本将 李启彬[1] 

机构地区：[1]西南交通大学地球科学与环境工程学院,成都611756 [2]四川碧朗科技有限公司,绵阳621900

出　　处：《环境工程学报》2015年第7期3571-3578,共8页Chinese Journal of Environmental Engineering

基　　金：中央高校基本科研业务费科技创新项目(SWJTU09CX059)

摘　　要：掺硼金刚石膜(BDD)电极是一种理想的用于电化学分析微量重金属离子的非汞电极,选择合适的BDD电极类型和探索简便的活化BDD电极的方法对提高其电分析检测能力和延长其使用寿命具有重要意义。本研究考察了3种硅基掺硼浓度(B原子浓度分别为2×1020/cm3、8×1020/cm3和27×1020/cm3,简写为BDD-2、BDD-8和BDD-27)的BDD电极经历相同的阴极预处理:在0.5 mol/L H2SO4溶液中,阴极恒电位(-3V vs.饱和甘汞电极)极化5、10、20、30和50 min后,以铁氰化钾/亚铁氰化钾为氧化还原探针,用交流阻抗和循环伏安技术表征了阴极极化后的BDD电极的电化学活性,并用阳极溶出伏安法,通过对一系列已知浓度的铅离子的测量试评估了阴极活化的效果。结果表明,电化学阴极预处理能显著提高3种掺硼浓度的BDD电极的表面活性,但阴极活化效果与BDD的掺硼浓度和阴极预处理时间有关,BDD-27和BDD-8的最佳阴极预处理时间分别为30 min和10 min,BDD-2因表面活性太差并不适合用于电分析。Boron-doped diamond（BDD） electrode is an ideal mercury-free electrode for electrochemically determining trace heavy metal ions.It is of great importance to improve the BDD electrode＇s performance and to extend its service life by selecting the correct type of BDDs and adopting a convenient means to activate the selected BDD electrode.An electrochemically cathodic polarization（-3 V vs.SCE） with a varying polarization duration（5-50 min） was carried separately out to three types of BDDs with a boron doping level of 2 × 1020/ cm3,8 × 1020/ cm3,27 × 1020/ cm3BDD（short for BDD-2,BDD-8 and BDD-27,respectively） in 0.5 mol/L H2SO4 solution.Electrochemical impedance spectroscopy（EIS） and cyclic voltammetry（CV） were used to evaluate the surface activity of the BDDs with and without cathodic polarizations by using 1.0mmol/L Fe（CN）3-/4-6.Moreover,the surface activity of the polarized BDD electrodes was examined further by using anodic stripping voltammetry to detect a series of known concentrations of Pb2 ＋.The results indicated that the cathodic polarizations significantly improved the surface activity of the three-type BDDs; however,the activation efficiency of the cathodic polarization was dependent on the boron doping level and the cathodic pretreatment time.An optimal cathodic pretreatment duration for BDD-27 and BDD-8 was found to be 30 min and 10 min,respectively,while BDD-2 was not suitable for electroanalysis due to its inferior surface properties.

关 键 词：掺硼金刚石膜电极 电化学阴极极化 交流阻抗 循环伏安 阳极溶出伏安法 铅离子测试 

分 类 号：O657.1[理学—分析化学]