Abstract
Solar-driven interfacial evaporation (SDIE) holds great promise for sustainable water purification and desalination. However, the complicated fabrication procedures of evaporators remain a challenge. More critically, many existing evaporators rely on polymer networks as mechanical skeletons, which often compromise porosity and water transport, leading to limited evaporation rates. Here, we report a polymer-free self-supporting graphene aerogel prepared via partial chemical reduction of graphene oxide (GO). During reduction, the GO sheets crosslink through strong π-π stacking interactions, forming a three-dimensional porous network in which the reduced graphene itself serves as the structural backbone. The resulting aerogel features high hydrophilicity, broadband light absorption of approximately 97% under wet conditions, and a porous architecture that facilitates rapid water transport and steam escape. By systematically varying the GO sheet size and concentration, we reveal how these parameters govern the aerogel’s intermediate water content, which collectively determine the evaporation performance. The optimized aerogel achieves an evaporation rate of 3.98 kg m−2 h−1 and an efficiency of 96.03% Under 1 sun illumination, with >99.9% ion rejection and stable cycling performance. This work establishes a structure-property relationship in polymer-free graphene aerogels, offering insights for designing high-performance solar evaporators beyond conventional polymer-based systems.