Water harvesting properties of a zwitterionic metal-organic framework

Abstract

Due to the rising scarcity of clean water in arid climates, there is an increased relevance in accessing clean and renewable water resources. One such perspective method, sorption-based atmospheric water harvesting, collects atmospheric water as an alternative to ground and surface water. Metal-organic frameworks (MOFs) are proposed as excellent porous materials for the capture and storage of small molecules, including water, owing to their large pore volume, high surface area, and chemical and structural tunability. Here a zwitterionic MOF (Ni-ZW-MOF), [Ni(dcpb)(H2O)4·14H2O]n, was synthesized and studied for its water sorption performance, displaying selective water adsorption and desorption capabilities. Respective sorption properties were tested in controlled low and high humidity environments over multiple cycles, demonstrating its regenerative ability and high working capacity (126.4 mL kg−1 per cycle).