甲壳素/高锰酸盐水系下含氧空位的三维贯通介孔纳米二氧化锰的可控制备

Manganese dioxide is a promising supercapacitor electrode material with high energy. However, the still poor electrochemical performance, such as its poor conductivity, low real specific capacitance and etc., prohibits its practical applications. Referring to the energy storage mechanism of supercapacitors and present investigations of structure and performance, to construct a 3D network mesoporous nano-MnO2 with oxygen vacancies is efficient and feasible for its electrochemical performance improvement. Since such a structure can not only make it have good rate capability and cycling stability, but also enhance its real specific capacitance by promoting its Faradic reaction. However, due to the disadvantages of bad controllability, low productivity and so on, presently main synthetic methods for porous materials (e.g. template, hydrothermal) are not fit for its preparation..Here, a simple, eco-friendly and controllable approach is proposed by selecting chitin and permanganate as raw materials to form such a 3D network mesoporous nano-MnO2 with oxygen vacancies, in considering of the advantages of our recently developed controllable and “green” sol-gel like method and the nanofiber structure nature of chitin. In order to regulate the structure and electrochemical properties, and controllably fabricate such 3D network mesoporous MnO2 with high electrochemical performance, the formation mechanism of MnO2, influences on the constructing of 3D networks and oxygen vacancy, the relationship between the oxygen vacancy content and the electrochemical properties of MnO2 and etc. are systematically studied. Through implementation, this project is not only expected to develop a new controllable, green and economy preparation technology of large specific surface area mesoporous oxide materials with independent intellectual property rights, but also to provide important theoretical guidance and reference for the design of high-performance porous electrode materials and the development of sol-gel method.

二氧化锰是一类极具实用潜能的新型高能量电容器电极材料。但是，导电性差、实际比电容低等问题制约其实际应用。根据赝电容储能机理和结构与性能关系，构筑含氧空位三维贯通介孔纳米MnO2，既能使其具有良好的倍率性能和循环寿命，又能促进MnO2的法拉第电化学反应，提高其比电容，从而实现二氧化锰电容综合性能的提升。.鉴于目前模板、水热等制备方法可控性差、产率低等问题，本项目以生物质甲壳素和高锰酸盐为原料，利用我们发展的类溶胶凝胶“绿色”可控制备新方法和甲壳素天然的纳米纤维结构，通过对该体系下二氧化锰的构建机理、三维贯通介孔结构及氧空位的合成条件、氧空位含量与电性能关系等的系统研究，实现高电容综合性能含氧空位三维贯通介孔纳米MnO2的可控制备。本项目的实施不仅有望形成具有自主知识产权的绿色环保的大比表面积介孔材料制备的新方法，而且对新一代高性能多孔电极材料的设计和溶胶凝胶法的发展提供重要的理论指导和参考。

二氧化锰是一类极具应用潜力的新型高能量电容器电极材料。但是，导电性能差、实际比电容低等问题制约其实际应用。为了实现二氧化锰电容性能综合提升及材料的低成本、可控制备，本项目通过对甲壳素/高锰酸钾反应体系下二氧化锰构建机理、合成条件、氧空位及电化学性能等的系统研究，弄清了产物形貌、微结构调控的关键因素、氧空位对材料结构及电化学性能的主要作用或影响，初步实现了高电综合性能三维贯通介孔纳米MnO2的设计和“可控”制备。在研究中，发展了适于产业化生产大比表面积介孔二氧化锰和纳米线二氧化锰的绿色合成新方法，初步证实所得二氧化锰可作为水中阳离子染料的吸附剂和催化剂以及低温合成锰酸盐的原料。本项目的顺利完成，不仅开发了具有自主知识产权的绿色环保的多孔材料制备新方法，对新一代高性能电极材料的设计、低成本构建具有重要的理论指导和参考，而且初步证实了本项目所得介孔二氧化锰在多个领域，如环境、催化、传感等，具有较好的应用前景。