Biomimetic coral skeleton-inspired solar evaporator from coconut fiber residue for efficient and stable seawater desalination

Solar-driven interfacial evaporation has become a highly promising approach to mitigate freshwater scarcity. However, developing green and sustainable solar evaporators that effectively balance heat localization and salt rejection remains a major challenge for real-world applications. Herein, inspired by the radial hierarchical microchannels in coral skeletons, we constructed a biomimetic evaporator (CRFB 6 -Gel@MC) by functionalizing coconut residue fiber-based aerogel (CRFB 6 -Gel) with solar-thermal composite (MXene@CDs, MC). The CRFB 6 -Gel@MC evaporator enabled simultaneous continuous water transport and salt reflux while preventing heat dissipation to bulk water, demonstrating effective decoupling of the long-standing conflict between salt rejection and heat localization. Under 1 sun illumination, the CRFB 6 -Gel@MC demonstrated a high evaporation rate of 4.66 kg·m −2 ·h −1 (65% higher than traditional evaporator with vertically aligned channels) and 91.3% solar-to-vapor efficiency. In addition, the evaporator exhibited zero salt crystallization after 8 h at 3-sun intensity in 20 wt% brine, validating its long-term operational stability. This work not only demonstrates the untapped potential of agricultural waste valorization but also establishes a biomimetic design paradigm for high-efficiency solar desalination systems.