Solar-driven dye wastewater purification and synergistic desalination by an aerogel-based multitasking platform...

For water remediation devices, enhancing the capability to perform multiple tasks and adapt to complex water environments remains a huge challenge. Herein, we reported an aerogel-based platform built with polydopamine-hybridized covalent organic frameworks (COF-R/PDA) for synergistic dye degradation and desalination. By engineering the types of heteroatoms (-C-, -O-, -S- and -N-) of the COF chain linkers, the key structural and physicochemical properties of aerogels, including porous architecture, hydrophilicity, and thermal conductivity, are precisely tuned. The optimal COF-N/PDA aerogel demonstrates an exceptional performance due to a synergistic mechanism: the host-guest COF-R/PDA interaction optimizes the electronic structure, facilitating charge separation/transport for photocatalytic dye degradation (99% removal) while enhancing photothermal conversion simultaneously for solar evaporation (1.91 kg m⁻² h⁻¹ rate, 90% efficiency). The platform can work well in diverse scenarios, from treating dye-contaminated seawater to purifying natural pond water. When deployed as a large-scale device (with 3 × 3 aerogel modules) for purifying natural water, the daily collected fresh water remains a competitive level, about ∼12 kg m^-2. This work proposes a promising strategy of manufacturing multitasking water remediation platform with superior water environmental adaptability based on the monolithic COFs.