Molecular sieves hybrid metal–organic framework for efficient simultaneously capturing carbon dioxide and collecting water from air

Abstract

Water scarcity and climate change associated with global warming are two common challenges facing humankind. The simultaneous removal of water and carbon dioxide (CO2) from the air has become a popular candidate strategy to address these challenges. In this paper, molecular sieve@MOF composites were synthesized in-situ for the first time by adding ZSM-5 and HZSM-5 during the preparation of Mg/DOBDC. A comprehensive review of the air capture CO2 and water harvesting properties of the novel composites was also presented. Primarily, the effects of molecular sieve category and ratio on the composite were systematically investigated. Subsequently, the crystal structure, morphological composition and textural properties of the composites were characterized. Finally, CO2/H2O co-adsorption performance, adsorption and desorption cycle stability and adsorption mechanism were investigated. The results demonstrated that the metal nodes of Mg/DOBDC interacted with the molecular sieve surface functional groups to increase the metal active sites and porosity. The obtained 0.5HZSM-5@Mg/DOBDC MOF showed the maximum CO2 uptake of 15.90 mmol/g (0.1 MPa, 25 °C), which was 3.66 times the amount of Mg/DOBDC.