Providing reliable access to clean and safe water is a major global challenge in the 21st century. Therefore, producing potable water from contaminated sources in a sustainable, low-energy approach is of paramount importance to address the water scarcity problem. Inspired by nature, a solar absorber gel (SAG) was developed to purify water from contaminated sources using only natural sunlight. The SAG was composed of an elastic thermo-responsive poly(N-isopropylacrylamide) (PNIPAm) hydrogel, a photothermal polydopamine (PDA) layer, and a sodium alginate (SA) network. Remarkably, the SAG can purify water from various harmful reservoirs containing small molecules, oils, metals, and pathogens, using only sunlight. The SAG relies on solar energy to drive a hydrophilic/hydrophobic phase transformation at the lower critical solution temperature. Since the purification mechanism does not require water evaporation, an energy-intensive process, the passive solar water-purification rate (a water purification rate of 7.18 kg m−2 h−1) is amongst the highest reported. This discovery can be transformative in the sustainable production of clean water to improve the quality of human life.

Bioinspired elastic hydrogel for solar-driven water purification

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.