离子液体-多金属氧酸盐纳米材料的低热固相合成及电催化性能

Polyoxometalates(POMs) have attracted considerable interests for their application prospects in many fields of electrochemistry, optics and catalysis owing to their novel structures and properties. POM anions have been also found to be versatile inorganic building blocks. The combination of the inorganic building blocks with appropriate organic molecules has been shown to lead to a variety of organic-inorganic hybrid materials that have the new functional properties. Ionic liquids(ILs) presented potential application prospects in electrochemistry owing to their high conductivities, low vapour pressures and good stabilities. Because the sensitivities, long term stabilities and repeatabilities of routine polyoxometalate modified electrodes are not good. As a result, the explorations of novel organic-inorganic hybrid materials are expected to be one of the important solutions. In this project, we combine the versatile electrochemical properties of ILs and POMs as well as the advantages of nanomaterials to facile synthesize novel organic-inorganic IL-POM nanomaterials by low-heating solid-state chemical reaction. As-prepared IL-POM nanomaterials were fabricated bulk-modified carbon paste electrodes (CPEs), which have many advantages of inexpensive and easy to renew the surface, to investigate their electrocatalytic activities toward the reduction of nitrite, bromate and hydrogen peroxide in environments and foods. The correlation between structures, morphologies, sizes and electrochemical properties of as-prepared materials were systematically studied to find the corresponding disciplinarian. This project would provide a new way to the researches, explorations and applications for novel green electrochemical sensor materials.

多酸具有独特的结构和性质，使其在电化学、光学、催化等领域应用广泛。多酸还是优秀的无机构筑块，与有机体结合, 能形成具有新型功能特性的有机-无机杂化多金属氧酸盐。离子液体具有导电率高、蒸汽压小、稳定性好等特点，使其在电化学领域的应用不断拓展。由于常规多酸修饰电极的灵敏度、长期稳定性及重复性较差，因此，开发新型有机-无机杂化材料成为改善多酸修饰电极电催化性能的一个重要解决办法。 本项目将离子液体和多酸的优良电化学性能以及纳米材料的特性三者有机地结合起来，采用低热固相化学反应这种简便、高效的纳米材料合成方法制备新型有机-无机杂化离子液体-多金属氧酸盐纳米材料。将其构筑成廉价、易更新的化学修饰碳糊电极，研究其对亚硝酸盐、溴酸盐、过氧化氢等环境及食品中污染物的电催化性能。系统探讨合成材料的结构、形貌、尺寸与电催化性能之间的关系，找寻有益规律，为新型绿色电化学传感器材料的研究、开发和应用开拓新思路。

随着人们对环境保护和食品安全的意识日益增强，开发新型高灵敏度、稳定、快速、简便的绿色电化学传感器是当前材料化学研究领域的重要任务之一。本项目将多金属氧酸盐、离子液体的优秀电化学性能与纳米材料的特性三者相结合，设计、合成了不同烷基链长的咪唑型、吡啶型、季铵型离子液体作为有机配体，采用低热固相化学反应法制备系列离子液体-多金属氧酸盐一维纳米棒、纳米六边形、纳米多面体、纳米粒子等纳米材料，探讨其反应机理可能是由于表面活性剂辅助的固相反应，离子液体在固相反应中既作反应物，同时又充当了表面活性剂。对比固、液相产物的形貌，后者尺寸较大、有团聚现象，甚至有些产物得不到在固相反应中的纳米结构，表明低热固相化学反应可为制备和研究多金属氧酸盐基纳米结构材料探索新途径。将合成的系列离子液体-多金属氧酸盐构筑成廉价、易于更新的碳糊修饰电极，用于研究其对亚硝酸盐、溴酸盐、过氧化氢等的电催化性能，系统探讨材料的结构、形貌、尺寸与电催化性能之间的关系，发现：(1) 对于相同的多金属氧酸盐，粒径小、且均匀的产物的电化学响应强于尺寸较大、团聚的产物；(2) 三种类型多金属氧酸盐的电化学响应均随烷基链的链长增加而减弱，这可能是由于有机配体离子液体的导电性均随烷基链的链长增加而减弱所致。研究所得的相关规律，为新型绿色电化学传感器材料的研究、开发和应用奠定了理论基础。 . 同时，在本项目研究的启发下，申请者将合成的材料应用于燃料电池阳极Pt基、Pd基催化剂的制备，发现能明显提高催化剂的抗CO中毒能力和催化活性。申请者由此而获得了“新疆维吾尔自治区自然科学基金”和“新疆维吾尔自治区优秀青年科技人才培养项目” 的资助。因而本项目的研究为申请者拓宽思路、积极创新提供了有益借鉴。