LiCl in situ decorated metal–organic framework (MOF)-derived porous carbon for efficient solar-driven atmospheric water harvesting

Abstract

Solar-powered sorption-based atmospheric water harvesting (AWH) technology is a promising solution to the freshwater scarcity in arid regions. Existing adsorbent materials still face challenges in aspects such as cycling stability and adsorption kinetics and require further development. Herein, we presented a strategy for the in situ fabrication of high-performance adsorbents, lithium chloride (LiCl)-decorated metal–organic framework (MOF)-derived porous carbon sorbents (PCl), via high-temperature pyrolysis and hydrogen chloride (HCl) vapor treatment. The sorbents display high adsorption capacity across a wide range of humidity water adsorption capacities in a wide humidity range with the maximum adsorption capacity of 7.87 g g⁻¹, and rapid response to the solar-driven process and excellent cyclic stability. The LiCl nanocrystals in PCl can be utilized efficiently and decorated within the porous framework stably, and demonstrate water adsorption at 20%, 40%, 60% and 80% RH, of 1.34, 1.69, 2.56 and 4.23 g_H2O·g_LiCl−1, respectively, and significantly higher water uptake and release rates than bulk LiCl. This may provide new guides for designing efficient solar-driven AWH.