An arch-bridge photothermal fabric from hydrophobic warp hair and hydrophilic weft grooved cellulose fiber for efficient waster evaporation and solar seawater desalination

Solar seawater evaporation technology plays a crucial role in alleviating the global freshwater scarcity crisis. However, some deficiencies involving complex preparation process, excessive solar heat loss and low evaporation rate have impaired its further application and extension. Therefore, this work proposes a facile and scalable strategy based on wet spinning and shuttle weaving technologies to fabricate a sustainable photothermal fabric with unique warp-weft and arch-bridge structures for the simulated seawater desalination. It is hypothesized that 1) the hydrophobic modified waste hairs with abundant melanin can serve as natural photothermal evaporative warp to finalize an efficient photothermal conversion; 2) the hydrophilic wet-spun fibers with numerous grooves can function as water conductive weft to reduce the evaporation enthalpy of water, thus facilitating water transmission rate and the solar evaporation rate; 3) the arch-bridge and warp-weft designs of the photothermal fabric can allow a lower solar heat loss to deliver an efficient solar water evaporation. Consequently, under a simulated sunlight condition of 1 kW·m −2 , the evaporation rate of the fabric in deionized water and 3.5 wt% NaCl solution can reach 2.34 kg·m −2 ·h −1 and 1.91 kg·m −2 ·h −1 , respectively. Therefore, this work has successfully fabricated a sustainable arch-bridge photothermal fabric with excellent evaporation rate, providing an alternative insight for solar interface evaporation fabrics.