Seawater desalination is a promising approach for freshwater production, however, it is somewhat limited by the energy intensity of the process and, perhaps more crucially, the need for access to bodies of salty water render it unsuitable for dry landlocked regions. In search of a broader solution, atmospheric water harvesting (AWH) has emerged as an alternative capable of providing a supplementary, geographically unrestricted source of fresh water. The water in air is estimated to be 1.3 x 10 L, far exceeding the volume of fresh water in all of the world's rivers (2.1 x 10 15 L). AWH exploits atmospheric water by using sorbent materials to passively capture water from air and concentrate it at their surface. Upon the application of some trigger, such as heat, the water is then desorbed from the sorbent in a controlled manner for harvesting. Ideal sorbents for AWH should display long-term stability upon exposure to water and heat, good working capacities below 30% relative humidity (RH), and heat of adsorption favourable to low-energy water desorption. Zeolites 7 and hygroscopic metal salts 8 display good water-sorption capacities, but typically suffer from high adsorption enthalpies, rendering water release energetically demanding.