Improved adsorption desalination performance of DUT-67 by incorporating Graphene Oxide (GO)

Abstract

Metal-organic frameworks (MOFs) have been recognized as one of the most promising adsorbents for adsorption desalination system (ADs) owing to their ultrahigh surface area. DUT-67 is a water-stable MOF with superior adsorption capacity, which has been demonstrated as a potential candidate for ADs. To further improve its desalination performance, in this work, different amounts of graphene oxide (GO) was incorporated with DUT-67 to obtain DUT-67/GO composites. The adsorption desalination performance including specific daily water production (SDWP) and performance ratio (PR) of DUT-67/GO composites under varying operating conditions were estimated by a lumped-parameter model. It is found that the mesopores in DUT-67/GO composites are favorable for the mass transfer. Among various DUT-67/GO composites, the DUT-67/GO composite with 24 wt% GO addition (DG-24) exhibited the highest water uptake (0.34 g/g) and overall mass transfer coefficient (0.0019 s−1), which were increased by 12.4% and 15.1% compared to DUT-67. Moreover, the average SDWP (14.7 m3/(ton/day)) and PR (0.77) of DG-24 were significantly improved by numerical simulation compared with DUT-67 (SDWP = 12.8 m3/(ton/day), PR = 0.72), which can be ascribed to their increased pore size and mass transfer coefficient.