Activated carbon-based light-absorbed layer in solar-driven water evaporation for clean water production

Solar-driven interfacial evaporation has emerged as a promising strategy for sustainable water purification. Here, low-cost solar-absorbing materials are fabricated using activated carbon (AC) with particle size in range of a few nanometer to over 140 micrometers, polyvinyl alcohol (PVA), and cotton fabric for efficient solar steam generation. The AC/PVA/cotton membrane exhibited broadband solar absorption exceeding 95% and achieved an evaporation rate of 2.4 kg·m-2·h-1 under 1 sun illumination. The membrane demonstrated excellent thermal stability, mechanical integrity, and optimal photothermal performance at 0.2 g AC loading. When tested with real water samples from Ha Long Bay and Van Quan Lake, the system effectively removed a range of ionic and heavy metal contaminants, including complete elimination of NO2-, Pb2+, and As3+ to undetectable levels. These findings confirm the membrane's potential for practical application in decentralized, off-grid water treatment systems, addressing global water scarcity through clean energy-enabled purification.