Hierarchically porous and high-strength carbon aerogel-based composite for solar-driven interfacial evaporation

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.