节点文献
多金属氧酸盐基的复合材料修饰电极、电化学及电催化研究
【作者】 王秀丽；
【导师】 王恩波；
【作者基本信息】 东北师范大学 ， 无机化学， 2003， 博士
【摘要】 本论文从所需要材料的功能特性出发，采用分子设计原理，有目的地的选择有机官能团制备了多金属氧酸盐基的复合材料，探讨了将这些复合材料用做修饰剂制备稳定性好的溶胶-凝胶薄膜修饰电极以及高稳定的、表面可更新的本体修饰碳糊电极和石墨有机硅复合电极的可行性，并研究了它们的电化学和电催化性能。主要研究结果如下： 1．设计并通过室温固相反应制备了无机·有机杂化的多金属氧酸盐纳米粒子，通过溶胶-凝胶技术首次将这种纳米粒子修饰到蜡浸石墨电极的表面，并系统研究了这种纳米粒子修饰电极(P2Mo18-WIGE)的电化学行为。该修饰电极可以催化氯酸根、亚硝酸根和过氧化氢的还原。其主要优点是长期稳定性好，这主要归因于杂化纳米粒子的不溶性。 2．以钼磷酸为例设计合成了其十六烷基吡啶的杂化物(C21H38N)3PMo12O40·H2O，并首次将这种杂化物用做本体修饰剂通过直接溶剂混合法制备了表面可更新的化学修饰碳糊电极；通过电化学方法表征了该修饰电极。该修饰电极对亚硝酸根、溴酸根和过氧化氢的还原表现出很好的电催化活性。该修饰电极的主要优点有两个：（1）当电极表面被污染时可以通过挤出一点碳糊很方便地更新，这对实际应用来说十分重要，而且制备简单、价格便宜；（2）稳定性好，这主要归因于这种杂化物的不溶性、C21H38N+对糊液的亲和力以及PMo12在石墨上的强吸附。 3．探讨了以无机-有机杂化的多金属氧酸盐纳米粒子为本体修饰剂通过研磨混合法制备了表面可更新的化学修饰碳糊电极的可行性。该修饰电极在酸性水溶液中的电化学行为通过循环伏安和方波伏安进行了表征。结果表明该修饰电极对亚硝酸根、溴酸根和过氧化氢的还原有很好的电催化活性。该修饰电极的优点是表面可更新且长期稳定性好。4．铝磷酸化学掺杂的聚毗咯被首次用做本体修饰剂制备了化学修饰 的碳糊电极。该修饰电极充分利用了多金属氧酸盐掺杂的聚合物的 优点和碳糊电极表面可更新的特性，对过氧化氢的还原表现出很 高的电催化活性，因此可被用做过氧化氢测定的电化学传感器，一 旦表面受到污染可以很方便的更新。5．设计合成了含有三c＊。联毗陡广和多金属氧酸盐的电活性复合物 RllPMO12和 RuSZMO18，并首次将它们用做双功能电催化剂通过直 接混合法制备了本体修饰的碳糊电极限 (PE似及通过溶胶 －凝胶技术制备了本体修饰的石墨有机硅复合电极（RIJSZMO；。－ GOSE），并通过循环伏安研究了它们的电化学行为。这两种不同方 法制备的双功能化学修饰电极不仅对过氧化氢和澳酸根的还原表 现出良好的电催化活性，这主要归因于多金属氧酸盐的功能，而且 对亚砷酸根的氧化也表现出很好的电催化活性，这主要是三口，2’－ 联毗陡广的功能。该修饰电极也同样具有表面可更新且长期稳定 性好的优点。6．以Lindquis－型多金属氧酸软Mo。O；／－做非配位的阴离子模版构筑 了一系列新的、三维的、澜系－芳香单竣酸二聚物的超分于网络： ［Ln。（DNBA）4（DM）s］［Mo0O10］(Ln—La，Ce 2和 Eu 3，DNBA—3上 二硝基苯甲酸，DMF一二甲基甲酚胺X 并通过元素分析、红外和 X－ 射线单晶衍射进行了表征，井研究了它们的电化学性质。
【Abstract】 1. Inorganic-organic hybrid polyoxometalates nanoparticles have been designed and prepared by solid-state reaction at room temperature and immobilized on the surface of wax impregnated graphite electrode (WIGE) by the sol-gel technique for the first time. The electrochemical behavior of the nanoparticles modified WIGE (P2Mo18-WIGE) has been studied in detail, including pH-dependence, solvent effect and stability. The electrocatalytic behavior of the P2Mo18-WIGE toward the reduction of chlorate, nitrite and hydrogen peroxide in 1 M H2SO4 aqueous solution is reported. Experimental results show that the P2Mo18-WIGE not only maintains the electrochemical activity and electrocatalytic properties of the H6P2Mo18O62, but also shows remarkable stability due to insolubility of the hybrid POM nanoparticles, which is important for practical application.2. PMo12-based inorganic-organic hybrid material (C21H38N)3-PMo12O40-H2O was designed, synthesized and firstly used as a bulk-modifier to fabricate a renewable three-dimensional chemically modified carbon paste electrode (CPE) by direct mixing. Electrochemical method was used to characterize the modified CPE. The hybrid material bulk-modified CPE (HM-CPE) not only displays good electrocatalytic activity toward the reduction of nitrite, bromate and hydrogen peroxide, but also exhibits a remarkable advantage of renewability in the event of surface fouling, as well as simple preparation and inexpensive material. Another remarkable advantage of the HM-CPE is its excellent stability due to insolubility of the inorganic-organic hybrid material, the affinity of the C21H38N+ toward the paste and the adsorption of PMo12 on graphite, which is important for practical application.3. Inorganic-organic hybrid polyoxometalates nanoparticles was firstly used as a bulk-modifier to fabricate a three-dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution is characterized by cyclic and square-wave voltammetry. The hybrid 18-molybdodiphosphate nanoparticles bulk-modified CPE (MNP-CPE) displays a high electrocatalytic activity towards the reduction of nitrite, bromate and hydrogen peroxide. The remarkable advantages of the MNP-CPE over the traditional polyoxometalates-modified electrodes are their excellent reproducibility of surface-renewal and high stability owing to the insolubility of the hybrid 18-molybdodiphosphate nanoparticles.4. Keggin-type phosphomolybdate (PMo12)-doped polypyrrole (PPy) prepared by chemical syntheses was firstly used as a bulk-modifier to fabricate a chemically modified carbon paste electrode (CPE) by direct mixing. Both the advantage of polyoxometalates (POMs)-doped polymer and surface-renewal property of the CPE are fully utilized. The PMou-PPy bulk-modified CPE also showed high electrocatalytic activity toward the reduction of hydrogen peroxide. A hydrodynamic voltammetric experiment was performed to characterize the electrode as an amperometric sensor for the determination of hydrogen peroxide. The sensor can be renewed easily in a repeatable manner by pushing a little carbon paste out.5. The electroactive composites containing tris(2,2’-bipyridine) ruthenium(II) and polyoxometalates RuPMo12 and RuS2Mo18 were synthesized and firstly used as a bifimctional electrocatalysts to fabricate a chemically bulk-modified carbon paste electrode (RuPMon-CPE) by direct mixing and graphite organosilicate composite electrode (RuS2Mo18-GOSE) by sol-gel process. The electrochemical behavior of the RuPMo12-CPE and RuS2Mo18-GOSE was studied by cyclicvoltammetry. The RuPMo12-CPE and RuS2Mo18-GOSE present good electrocatalytic activity not only toward the reduction of hydrogen peroxide and bromate, which is attributed to the function of polyoxometalates, but also toward the oxidation of arsenite, which is