Abstract:

Carbon aerogel is a kind of porous carbon nano materials with low density, high porosity, high specific surface area, excellent electrical conductivity and good mechanical properties. Therefore, it has become a hot spot and an important direction in the research of carbon materials. The purpose of this paper is to elucidate the development process of phenolic carbon aerogels and to highlight the development direction of phenolic carbon aerogels in the future. Based on this, the preparation methods of phenolic carbon aerogel are introduced in detail firstly, including three main steps: sol-gel, drying and carbonization process. Furthermore, the preparation of phenolic carbon aerogels with three different precursors, namely resorcinol, phenol and biomass tannin/lignin, as well as their advantages and disadvantages are described. Then, the applications of phenolic carbon aerogels as adsorption materials (gas/liquid adsorption), electrochemical energy storage materials and also for other fields are reviewed. Finally, the research direction and development prospect of phenolic carbon aerogels are summarized and prospected. It is pointed out that the traditional method of preparing phenolic carbon aerogel with resorcinol as raw material by supercritical drying method had high raw material cost and harsh reaction conditions, which limited its practical production and application. Replacing resorcinol with phenol or improving its preparation process by freeze-drying method can greatly reduce the raw material and production costs. However, the future development direction would be the systematic research of green and renewable biomass raw materials (tannin, lignin, cashew phenol, etc.) and the development of their composite materials. Therefore, in the future development of phenolic carbon aerogels, it is necessary to further improve the preparation process and method and broaden the source of raw materials to improve the performance and expand the application field.

Key words: phenol-formaldehyde resin, carbon aerogel, sol-gel, drying, pyrolysis, nanomaterials

摘要：

炭气凝胶是一种多孔纳米炭材料，具有低密度、高孔隙率、高比表面积、优异的导电性和良好的成型性能等优点，是炭材料研究的热点和重要方向。本文旨在通过阐明酚醛基炭气凝胶的制备原料和制备工艺的发展过程，从而突出未来酚醛基炭气凝胶的发展方向。基于此，本文首先重点介绍了酚醛基炭气凝胶的制备方法，主要包括溶胶-凝胶化、干燥以及炭化过程三个最主要的步骤；进而详述了以三种不同的前体，即间苯二酚、苯酚、生物质单宁/木质素分别制备酚醛基炭气凝胶的方法及其优缺点；接下来对酚醛基炭气凝胶作为吸附材料（气体吸附/液体吸附）的吸附量以及在电化学储能以及其他领域的应用进行了综述；最后对酚醛基炭气凝胶未来的研究方向和发展前景进行了总结和展望。文章指出，传统的以间苯二酚为原料辅以超临界干燥的方法制备的酚醛基炭气凝胶，原料成本较高，反应条件苛刻，实际生产应用受限；以苯酚取代间苯二酚，亦或是采用冷冻干燥等方法改进其制备工艺，可以大幅度降低原料和生产成本；但未来的发展方向和重点将是绿色、可再生的生物质原料（单宁、木质素、腰果酚等）及复合气凝胶材料的研发。因此，酚醛基炭气凝胶在未来的发展还需要进一步改进其制备工艺和方法，拓宽其原料来源，从而提高性能，扩大应用领域。

关键词: 酚醛树脂, 炭气凝胶, 溶胶-凝胶, 干燥, 热解, 纳米材料