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High-efficiency and low-cost solar-driven interfacial evaporation is a promising approach for seawater desalination on ships, islands, and offshore platforms. Thus far, various nanostructured interfacial evaporation materials have been developed, and chemical regulation, surface engineering, and other modification strategies have been applied. As a result, the evaporation rate of interfacial evaporation systems has significantly increased. However, interfacial evaporation materials still suffer from disadvantages such as high costs and complex preparation processes. Furthermore, nanostructured materials exhibit poor mechanical properties, which limit their practical applications. In this study, we prepared a hierarchical porous carbon fiber felt-reinforced carbon aerogel composite for interfacial evaporation applications. The composite exhibited low thermal conductivity, excellent mechanical properties, and high evaporation rates in both pure water and seawater under 1-sun illumination. Moreover, the composite maintained a stable evaporation rate and excellent cyclicity for a long period under 5-sun illumination in high-salinity seawater. The low cost of raw materials, simple preparation process, and short production cycle are beneficial for the large-scale production and application of this novel interfacial evaporation material. Highlights: The carbon aerogels prepared using the principle of acid-base two-step catalysis have a high specific surface area (596.367 m2g−1) and low thermal conductivity (0.0625 W/(m K)), which enable them to efficiently absorb sunlight and provide an excellent thermal insulation effect. The difference in shrinkage between carbon fiber felts and carbon aerogels is ingeniously utilized, so the composites have micron-scale macropores and defects to provide channels for vapor escape. Under 1-sun illumination, the evaporation rates of the composites reach 1.131 and 1.046 kg m−2 h−1 in pure water and seawater, respectively, with an evaporation efficiency of 81%. Due to the composite reinforcement of the highly elastic carbon fiber felts, the composites are able to endure a stress of 25.6 MPa when the strain reaches 75%. The strategy of carbon fiber felts reinforcement not only enhances the mechanical properties and durability of the composite but also avoids the brittle fracture of pure carbon aerogels. The obtained composites combine low-cost effectiveness with high mechanical properties and durability. [ABSTRACT FROM AUTHOR]

A low-density, high-specific surface area, high-strength and large-sized carbon aerogel preparation process is a key technology in the industrial application of aerogel science. In recent years, ingenious nanostructure design, along with salt templates, drying optimization and other strategies have been applied by numerous scientists. As a result, the specific surface area of carbon aerogel has significantly increased and the density reduced. However, the preparation of high-strength and large-sized intact carbon aerogel at low cost is still a challenge due to the limitations of thermal treatment equipment and drying process. In this study, we propose an improved preparation method of ambient pressure solvothermal polymerization and auxiliary ambient pressure drying by the principle of acid–base two-step catalysis using resorcinol and furfural as raw materials. Resultantly, the condensation and cross-linking reaction process is stabilized by the ambient pressure solvothermal polymerization, which effectively reinforces the interfacial bonding between primary particles and forms a high-strength skeleton. The breaking strength of the aerogels reach up to 9.74 MPa. The auxiliary ambient pressure drying can greatly reduce the drying shrinkage and density of the aerogel and solve the problems of drying deformation and cracking of large-sized carbon aerogel. The drying shrinkage and density of the obtained carbon aerogels are reduced to 3.22% and 0.203 g/cm3, respectively, and the specific surface area reaches 675.057 m2/g. Moreover, the large-sized sample (70 mm (d) × 25 mm (h)) can also be prepared by this method since the strength of skeleton can resist the capillary force of pore structure, and the nanoporous architecture can be perfectly retained. Therefore, this study provides a new preparation scheme for the industrial large-scale production and application of carbon aerogel. [ABSTRACT FROM AUTHOR]