Carbon fiber reinforced PVA-based aerogel with enhanced photothermal and mechanical performance for efficient solar-driven desalination

Abstract

Escalating dual pressures of global energy transition and freshwater scarcity have driven growing attention to water treatment leveraging low-grade, widely distributed renewable energy. Solar-driven interfacial evaporation stands out as a technically simple, low-infrastructure seawater desalination route, directly converting solar energy into localized heat at the evaporation interface and operating ambiently without external power, ideal for decentralized off-grid applications. However, most reported evaporators suffer structural collapse, inefficient heat management and long-term performance degradation in saline environments, due to loosely assembled photothermal layers or fragile porous scaffolds. Herein, a carbon black and chopped carbon fiber reinforced aerogel evaporator (CFA) is fabricated via poly(vinyl alcohol) crosslinking, integrating photothermal conversion, capillary water transport and structural support into a monolithic 3D architecture. Carbon black acts as cost-effective broadband solar absorber with robust photothermal stability, while short carbon fibers serve as mechanical reinforcements and thermal conduction bridges; their synergy with crosslinked PVA enhances light absorption, heat distribution and mechanical robustness synergistically. The CFA evaporator has a simple and scalable manufacturing process and stable evaporation performance under actual brine conditions. It shows the engineering-oriented design of durable and efficient solar evaporators, which provides a feasible way for scalable solar-driven seawater desalination to alleviate the global freshwater shortage.