Renovating waste textiles into honeycomb-mimic hydrogel-modified fabrics for cheap and efficient solar-driven desalination

Fibrous membranes have received increasing attention in solar-driven desalination, while they commonly suffer from low production efficacy and high cost during the spinning process. Focusing on the huge amount of waste textiles, this work converts them into hydrogel-modified renovated fabrics (HRF) for solar-driven desalination. The HRF has been prepared by extracting fibers from waste textiles made from polyacrylonitrile, waving into the honeycomb-mimic renovated fabrics (RF), and modifying with the hydrogel containing carbon black via chemical bath deposition, successively. The periodically concave pores of HRF promote multiple light absorption, yielding a high photoabsorption efficiency of > 98 % and good solar-thermal conversion. With the hydrogel modification, the water evaporation enthalpy decreases to 1668.1 kJ kg −1 compared with that (∼2400 kJ kg −1 ) of bulk water. The HRF-based hanging evaporator is then constructed and exhibits an evaporation rate of 2.58 kg m −2 h −1 and an efficiency of 94.1 % under sunlight irradiation. The hanging evaporator attains a stable evaporation rate without solid-salt precipitation under 24 h of irradiation, better than the floating evaporator. In addition, the HRF has a low overall cost of 7.2 $ m −2 . Therefore, this work offers insights into the reutilization of waste textiles in photothermal seawater desalination.