CuS-enhanced light-absorbing washable solar evaporator based on polydopamine-cotton fabric for efficient water purification

Interface solar steam generation (ISSG) is a prospective and reliable option for producing freshwater from seawater and industrial wastewater. However, salts and heavy metal ions deposited on photothermal materials (PTMs) will diminish the evaporation rate. Besides, the low evaporation rate will limit the widespread application of ISSG devices. In this work, we exploited a washable CuS-enhanced light absorption PTM based on polydopamine-cotton fabric (PDA-CF), which is abbreviated as CuS-PDA-CF. On one hand, CuS-PDA-CF is washable and can be cleaned by hand or ultrasonic to remove the deposited salts and renew the photothermal performance. On the other hand, Due to the cooperative contribution of CuS and PDA, the light absorption capacity of CuS-PDA-CF is improved to 98.13%, acquiring a 1.50 kg m(-2) h(-1) water evaporation rate with a 94.49% photothermal efficiency at 1-solar (1 kW m(-2)) illumination. Outdoor experiments demonstrate that the solar vapor generator based on CuS-PDA-CF can extract freshwater from seawater and industrial wastewater. The cations elimination rate in seawater and industrial wastewater is higher than 99.9%. This work provides an achievable method to fabricate efficiency-enhanced and washable CF-based solar evaporators to relieve freshwater scarcity.