物理化学学报 >> 2011, Vol. 27 >> Issue (02): 473-478.doi: 10.3866/PKU.WHXB20110208

电化学和新能源 上一篇    下一篇

Dawson型磷钨杂多阴离子P2W18O626-的电化学性质和对O2还原的电催化作用

王崇太1, 华英杰1, 孙振范1, 韦吉崇1, 李天略1, 童叶翔2, 刘晓旸3   

  1. 1. 海南师范大学化学与化工学院, 海口 571158;
    2. 中山大学化学与化学工程学院, 广州 510275;
    3. 吉林大学化学学院, 无机合成与制备化学国家重点实验室, 长春 130012
  • 收稿日期:2010-08-02 修回日期:2010-10-18 发布日期:2011-01-25
  • 通讯作者: 华英杰 E-mail:521000hua282@sina.com
  • 基金资助:

    国家自然科学基金(20963003), 海南重点科技基金(080305, 090803), 海南省自然科学基金(509009)和吉林省科技项目(20090595)资助

Electrochemical Properties of the Dawson-Type Heteropolytungstate Anion P2W18O626- and Its O2 Reduction Electrocatalysis

WANG Chong-Tai1, HUA Ying-Jie1, SUN Zhen-Fan1, WEI Ji-Chong1, LI Tian-Lue1, TONG Ye-Xiang2, LIU Xiao-Yang3   

  1. 1. School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, P. R. China;
    2. School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China;
    3. State Key Laboratory of Inorganic Synthesis Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
  • Received:2010-08-02 Revised:2010-10-18 Published:2011-01-25
  • Contact: HUA Ying-Jie E-mail:521000hua282@sina.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20963003), Key Science and Technology Foundation of Hainan Province, China (080305, 090803), Natural Science Foundation of Hainan Province, China (509009), Science and Technology Program Foundation of Jilin Province, China (20090595)

摘要:

用循环伏安、交流伏安和交流阻抗法对Dawson型磷钨杂多阴离子P2W18O626-的电化学性质进行了详细研究, 循环伏安结果显示, P2W18O626-在pH 2.52的0.1 mol·L-1 Na2SO4+NaHSO4溶液中有两对可逆的单电子还原-氧化波和两对可逆的双电子还原-氧化波. 单电子波的峰电位和电流与溶液的pH无关, 双电子波的峰电位则随溶液pH的增加而负移, 峰电流降低, 表明双电子电极过程有H+参与, 其数目为2. 交流阻抗谱表明P2W18O626-的电极过程完全受扩散控制, 实验测定其扩散系数(DO)为2.5×10-6 cm2·s-1. 循环伏安结果表明P2W18O626-的第III对波对O2还原为H2O2具有显著的电催化作用, 催化效率约达300%. 将P2W18O626-应用于PW11O39Fe(III)(H2O)4-构成的类电-芬顿过程, 使该过程对硝基苯的降解效率显著提高.

关键词: Dawson型磷钨杂多阴离子, 电催化, 氧还原, 过氧化氢, 硝基苯降解

Abstract:

The electrochemical properties of the Dawson-type heteropolyanion P2W18O626- were studied in detail by cyclic voltammetry, alternating current (AC) voltammetry, and AC impedance. Cyclic voltammetry results revealed that P2W18O626- possessed two pairs of reversible one-electron redox waves and two pairs of reversible two-electron redox waves in a solution containing 0.1 mol·L-1 Na2SO4 and NaHSO4 (pH 2.52). The peak potential and the peak current of the single-electron wave were independent of the solution pH while the peak potential of the two-electron wave shifted negatively, and the peak current decreased with an increase in solution pH. This indicated that the two-electron electrode process involved H+ and the involved H+ number was 2. AC impedance spectroscopy showed that the P2W18O626- electrode process was fully controlled by diffusion and the diffusion coefficient (DO) was 2.5×10-6 cm2·s-1. The cyclic voltammograms indicated that significant P2W18O626- electrocatalysis towards O2 reduction to H2O2 occurred as evidenced by the third wave pair and a catalytic efficiency of 300% were obtained. Application of P2W18O626- in the degradation of nitrobenzene in the electro-Fenton-like system containing PW11O39Fe(III)(H2O)4- showed a remarkable improvement in terms of degradation efficiency.

Key words: Dawson-type heteropolytungstate anion, Electrocatalysis, Oxygen reduction, Hydrogen peroxide, Nitrobenzene degradation

MSC2000: 

  • O646.5