Bioinspired PVA/CS/WPU@c-MWCNTs aerogel for concurrent highly efficient freshwater generation and hydrovoltaic power production

Addressing global energy and freshwater scarcity requires sustainable, integrated technologies. Inspired by sunflower's water transport mechanisms, we developed a hydrophilic composite aerogel based on polyvinyl alcohol (PVA), chitosan (CS), and waterborne polyurethane (WPU). Incorporating carboxylated multi-walled carbon nanotubes (c-MWCNTs) yielded the BMPCW aerogel, a bifunctional system for simultaneous solar desalination and hydrovoltaic power generation. This design synergizes the aerogel's interfacial evaporation properties with c-MWCNTs' conductivity and photothermal conversion, significantly enhancing water/ion transport and energy conversion efficiency. Under 1 kW m −2 simulated sunlight, the system achieved a high freshwater evaporation rate of 3.41 kg m −2  h −1 and generated an open-circuit voltage of 125.2 mV in 3.5 wt% sodium chloride (NaCl) solution. The BMPCW aerogel exhibits excellent chemical stability, renewability, and maintains robust performance over multiple cycles. Aerogel array devices successfully demonstrated applicability in seawater desalination and powering small electronics. This work highlights the aerogel's potential for distributed energy, smart agriculture, and offshore applications, offering a novel biomaterial strategy and feasible pathway for sustainable clean water and green energy co-production.