Super Water-Extracting Gels for Solar-Powered Volatile Organic Compounds Management in the Hydrological Cycle

Water-soluble volatile organic compounds (VOCs) are widely spread in the natural hydrological cycle, contaminating potential water sources, and leading to unexpected ecological hazards. However, water-purification technologies toward VOCs are energy-intensive and present unsatisfactory purity of the obtained water. The fundamental challenge is to differentiate the motion of water and VOC molecules by separators. Here, the concept of a super water-extracting gel (SWEG) for VOC-management and water purification via direct solar distillation is proposed. The strong hydrogen bonding effect in the hypercrosslinked hydrophilic polymeric networks enables the SWEG to extract water from VOC-containing water, which rejects the VOC solutes while allowing water through for interfacial evaporation. The obtained SWEG achieves a VOCs removal ratio up to 99.99% by solar distillation under 1 sun. A solar water-purification system is also demonstrated to produce clean water, which surpasses other competitive technologies based on electricity.