Research progress in the preparation and application of three-dimensional carbon aerogel materials

Carbon aerogels are a class of three-dimensional (3D) porous structure material comprising carbon materials. This structure combines the advantages of low density, high porosity, large specific surface area of aerogel as well as low thermal conductivity, high conductivity, high thermal stability, and strong chemical inertness of carbon materials. Recently, they have become one of the research hotspots in the functional material field. Due to their distinctive properties, carbon aerogel materials have attracted increasing attention and exhibited great application prospects in the areas of high-temperature insulation, energy storage, photothermal conversion, electromagnetic wave absorption, adsorption, and catalysis. The synthetic route for carbon aerogels has been developed rapidly. Raw materials used for their preparation are not only limited to conventional crosslinked phenolic prepolymers, but they also include graphite materials, biomass, and polymers. In this paper, carbon aerogels are categorized into three based on the raw material used: graphite-based, organic, and hybrid carbon aerogels. Moreover, the common preparation methods for 3D carbon aerogels are introduced, including sol–gel method, hydrothermal method, chemical vapor deposition, and ice template method, advantages and disadvantages of each preparation method are briefly described, and their effects on the structure and properties of carbon aerogel materials are analyzed. Furthermore, the applications of carbon aerogel materials in the fields of oil absorption, energy storage, heat insulation, catalysis, wave absorption, photothermal conversion, and flexible sensors are summarized. Carbon aerogel materials have the advantages of light weight, large specific surface area, and high adsorption capacity, making them superior to traditional oil absorption materials. These materials can be used as supercapacitor electrode materials, fuel cell catalysts, catalyst carrier materials, and flexible sensors owing to their high conductivity and stable electrochemical performance. They can also be used as effective electromagnetic wave-absorbing materials due to their good impedance matching characteristic. Additionally, their ultralow thermal conductivity enables them to have an excellent thermal insulation performance, and their wide light absorption range makes it have a good prospect in photothermal conversion applications. Finally, the current issues on the preparation and application of carbon aerogel materials are analyzed. Furthermore, future development trends and directions are prospected, including developing low-cost, renewable, and environmentally friendly precursor materials, optimizing the preparation process of carbon aerogels, reducing the production cycle, and broadening the high-end application fields of carbon.