Bi2S3/nylon membrane photothermal absorber with water shortage warning capability for seawater desalination

In the actual application process, solar photothermal absorbers are often easily blocked by pollutants in the water. Herein, a novel washable Bi2S3/nylon membrane (Bi2S3/NM) photothermal absorber with a visual water shortage warning was prepared by vacuum-assisted filtration method. It has 1.13 kg m−2 h−1 of evaporation rate and the light-steam conversion of 75.5% under 1-sun desalination performance. When the bottom water supply layer is blocked, the upper 2D photothermal absorber show a visual crimp alarm under the anhydrous light conditions. More importantly, the curly photothermal absorber can be regeneration by a simple washing process and then restore photothermal evaporation performance. This work gives a whole new perspective to improve convenience of solar photothermal absorbers the actual application process.