Perspective on metal-organic frameworks-based atmospheric water harvesting systems towards universal adoption

Abstract

Climate change and the unequal distribution of freshwater resources are contributing factors to the global water crisis. Metal-organic frameworks (MOFs) have become a viable material for atmospheric water harvesting (AWH) due to their function in low relative humidity (RH) conditions. Their potential in dry conditions is demonstrated by MOF-801's up to 0.3 L/kg MOF/day and MOF-303's 0.7–1 liter/kg MOF/day. MOFs' high porosity, adjustable adsorption characteristics, and reduced regeneration temperatures have made them stand out as better alternatives. In this review, MIL-101(Cr), MOF-801, and MOF-303 are recommended as appropriate for AWH applications due to their promising water adsorption capabilities. Studies have shown that MIL-101(Cr) can outperform conventional desiccants with a water uptake of up to 1.5 g/g. It is also discussed that MOFs are successful in arid areas where traditional methods are ineffective due to their exceptional selectivity for water adsorption, even in low-humidity conditions. In order to evaluate the most recent developments in MOF-based AWH technologies, this review compared their performance to that of current AWH techniques. Although the production of MOFs is still expensive, economic feasibility studies show that improvements in scalable synthesis techniques, such as green solvent-assisted fabrication, could drastically lower manufacturing costs. With current research concentrating on enhancing material stability to extend operational lifespans, MOFs' long-term viability is also greatly influenced by their durability and recyclability. Furthermore, total efficiency may be increased by hybrid AWH systems that combine MOFs with other adsorption materials, such as hydrogels. In this review, recent developments in MOF-based AWH systems are studied, with an emphasis on material characteristics, system performance, and large-scale viability.