Nanowerk November 4, 2023
Researchers in China have reported a kind of light-responsive MOF adsorption material which was fabricated by covalently immobilizing photoactive spiropyran (SP) molecules onto a chromium(III)-based amino-tagged MIL-101 framework through amide linkages. The photoisomerization of SP moieties provided these materials with reversible binding to metal ions. In the dark, the SP-modified MOFs were capable of adsorbing multiple monovalent and divalent salts from saline water and effectively released the adsorbed ions into water upon exposure to simulated sunlight. The MOFs showed excellent salt adsorption capacity, of which the MOF with an SP modification ratio of 39% had an ion uptake of 2.27, 1.72, 1.0, 0.8, and 0.39 mmol g–1 for the monocomponent solutions of LiCl, NaCl, KCl, CaCl2, and MgCl2, respectively. After 10 adsorption–desorption cycles, the regenerated adsorbent still exhibited a higher ion adsorption of 1.27 mmol g–1 for the NaCl solution. According to the researchers their work provides a synthetic strategy for salt adsorption materials with nonchemical regeneration ability for water desalination and purification… read more. TECHNICAL ARTICLE
Graphical abstract. Credit: ACS Appl. Nano Mater. 2023, 6, 19, 17996–18004Â