基于生物模板的分级孔炭材料制备科学与应用研究

Porous carbon with high specific surface area and plenty of pore structure has been considered as one of the most important materials for the energy conversion and environmental purification. Some basic scientific questions relating to the porous carbon, such as the mechanism of the accurately controlling of pore structures and surface states to achieve the 3-dimensional lamellar hierarchical porous carbon with functionalized surface have attracted much attention. This study based on the fine ordered nano-structure and composition of natural organic-inorganic composite, selects some kinds of biomass, such as animal bones and scales, as the raw material for the porous carbon, focused on investigating the effect of inorganic composite template (hydroxyapatite) and carbonization process from organic material (protein) to carbon structures, in order to figure out the formation mechanism of 3-dimensional interconnected hierarchical porosity and selective in-situ doping of surface elements, and the brand new synthesis method of hierarchical porous carbon from natural template is also developed. By further controlling the 3-dimensional lamellar interconnected hierarchical porosity and surface chemical state, the synergy effects of hierarchical porosity on the electron-transfer and mass transportation, along with the influence of surface state on the selective adsorption are studied. Based on the above investigations, the basic theories relating to the 3-dimensional lamellar interconnected hierarchical porous carbon based on the natural template applying for energy storage, conversion and environmental purification are established.

多孔炭以其高的比表面积和丰富的孔结构等优势成为能量转换和环境净化的关键材料之一。目前有关多孔炭的研究热点之一是通过对其孔道结构及表面化学状态的调控机制等基本科学问题的揭示，以实现具有立体层状分级孔结构炭材料的可控制备和高功能化。本项目从研究生物材料的结构入手，以动物骨和鱼鳞等食品废弃物为前驱体，利用其精美有序的分级层状纳米结构和组成排序，研究其中的无机化合物（羟基磷灰石等）模板的作用机制和有机生物质（蛋白质等）的碳化过程，揭示其层状立体连通分级孔结构的形成机制和表面元素的选择性原位参杂机理，形成全新的基于生物模板的分级孔炭材料的制备科学；通过对多孔炭的层状立体连通分级孔结构和表面化学状态的进一步精确调控，强化分级孔结构的协同效应对电荷迁移和反应中传质过程的影响以及表面化学状态对选择性吸附的作用机制，构建基于生物模板的分级多孔炭材料在能源转换/储存及环境净化方面的应用基础理论。

设计开发分级孔结构的多孔炭材料并实现可控制备和高功能化对能源转换/存储以及环境净化领域具有重要的理论意义。本项目以动物基（如牛骨、羊骨和鱼鳞）和植物基（如麻杆、豆根、丝瓜络、紫菜等）生物质为前驱体，通过碳化活化方法制备了系列具有分级孔结构、大比表面积（1500-2600 m2 g-1）且富含氮（1-4%）、氧（11-16%）杂原子的多孔炭材料。项目研究了碳化工艺对成炭机制的影响规律，从分子层面揭示了蛋白质等天然高分子分子链的低温交联、中温分子环化和高温成炭的机制，进而揭示了多孔炭材料的表面原位元素掺杂的控制机理；从微纳尺度探索羟基磷灰石等无机化合物模板的作用机制和多孔炭材料的层状结构（微）和分级孔结构（纳）的形成原理，实现了基于生物模板分级孔炭材料的成分与结构的有效调控。同时开展了该多孔炭材料在能源转换/存储以及环境净化等方面的应用基础研究，将制备的多孔炭材料用于锂离子电池、超级电容器、锂硫电池等电极材料、燃料电池电催化材料以及苯酚和重金属有毒离子的去除，揭示了其分级孔结构的协同效应对电荷迁移和反应中传质过程的影响规律以及其表面化学状态对选择性吸附的作用机制。研究表明，制备的分级多孔炭材料表现出优异的电化学储能、电催化和吸附性能，其独特的微孔-介孔-大孔相连的孔结构、高表面积和丰富的杂原子促进了性能的提升，有望应用于能源转换/储存以及环境净化领域。