作　　者： ; ; ; ; ; ; ;

机构地区： 海南师范大学化学与化工学院

出　　处： 《物理化学学报》 2011年第2期473-478,共6页

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P2W18O66-2的电化学性质进行了详细研究,循环伏安结果显示,P2W18O66-2在pH2.52的0.1mo·lL-1Na2SO4+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完全受扩散控制,实验测定其扩散系数(DO)为2.5×10-6cm2-1.循环伏安结果表明P2W18O6-62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P2W18O6-62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. The electrochemical properties of the Dawson-type heteropolyanion P2W18O6-62 were studied in detail by cyclic voltammetry,alternating current（AC） voltammetry,and AC impedance.Cyclic voltammetry results revealed that P2W18O6-62 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 P2W18O6-62 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 P2W18O6-62 electrocatalysis towards O2 reduction to H2O2 occurred as evidenced by the third wave pair and a catalytic efficiency of 300% were obtained.Application of P2W18O6-62 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.

关 键 词： 型磷钨杂多阴离子 电催化 氧还原 过氧化氢 硝基苯降解

领　　域： [理学] [理学]