Molecular Engineering of Hydrogels for Rapid Water Disinfection and Sustainable Solar Vapor Generation

Consumption of unsafe water is a major cause of morbidity and mortality in developing regions. Pasteurizing or boiling water to remove pathogens is energy-intensive and often impractical to off-grid communities. Therefore, low capital cost, rapid and energy-efficient water disinfection methods are urgently required to address global challenges of safe water access. Here, anti-bacterial hydrogels (ABHs) with catechol-enabled molecular-level hydrogen peroxide generators and quinone-anchored activated carbon particles are designed for effective water treatment. The bactericidal effect is attributed to the synergy of hydrogen peroxide and quinone groups to attack essential cell components and disturb bacterial metabolism. ABHs can be directly used as tablets to achieve >99.999% water disinfection efficiency within 60 min without energy input. No harmful byproducts are formed during the treatment process, after which the ABH tablets can be easily removed without residues. Taking advantage of their excellent photothermal and biofouling-resistant properties, ABHs can also be applied as solar evaporators to achieve stable water purification under sunlight (≤1 kW m^-2 ) after months of storage and operation in bacteria-containing river water. The ABH platform offers reduced energy and chemical demands for point-of-use water treatment technologies in remote areas and emergency rescue applications.