Volcano‐Inspired Dual‐Carbon Network Aerogel for High‐Performance Solar Evaporation With Edge‐Directed Salt Crystallization and Recovery

ABSTRACT The escalating global freshwater shortage demands sustainable and energy‐efficient desalination solutions. Here, a volcano‐inspired dual‐carbon‐network aerogel (CFCA) that couples hierarchical fluidic channels with multiscale thermal management for high‐performance solar desalination is developed. The CFCA features interconnected primary, branching, and microporous conduits within a carbon‐black aerogel, reinforced by dispersed short carbon fibers to form continuous capillary pathways for rapid water transport and vapor release. A continuous outer carbon‐fiber shell acts as a heat‐confining layer and thermal reservoir while directing salt migration toward the edges. The conical geometry generates radial temperature gradients that induce Marangoni convection, enabling spontaneous salt expulsion and edge‐localized crystallization without blocking the photothermal surface. Benefiting from these synergistic effects, the CFCA delivers an ultrahigh evaporation rate of 4.08 kg m −2 h −1 and a solar‐to‐vapor efficiency of 95.8% under 1 sun. It also maintains an evaporation rate of 2.63 kg m −2 h −1 in 20 wt.% brine with a salt recovery efficiency of 44.2%, and achieves an average rate of 3.00 kg m −2 h −1 during seven‐day operation in 3.5 wt.% saline water. This work establishes a comprehensive design strategy integrating efficient photothermal conversion, guided mass transport, and recoverable salt crystallization for scalable solar‐driven water purification and salt resource recycling.