Enhancing osmotic energy conversion with functionalized UiO-66-NH2-based heterogeneous membrane

Converting the salinity gradient between seawater and river water into osmotic energy is one of the direct and effective ways to alleviate the energy crisis. High selectivity and permeability are two contradictory aspects in the design of composite membranes , and balancing the relationship between the two is the key to achieving efficient osmotic energy harvesting . Herein, a series of heterogeneous membranes consisting of UiO-66-NH 2 intercalated with poly (sodium 4-styrenesulfonate) (PSS) and anodized aluminum oxide (AAO) were designed to enhance the osmosis power generation capacity. The asymmetry of pore size, surface charge, and wettability of the composite membrane makes it behavior like a diodes-like ionic current rectification (ICR). The addition of PSS changes the ion selectivity and permeability of the composite membrane, thus enhancing the energy harvesting performance. The maximum power density of 6.32 W/m 2 is obtained under a 50-fold salinity gradient, which is 4.94 times that of the original composite membrane. This study provides a reasonable preparation strategy for functionalized MOF-based composite membranes for ion transport and efficient osmotic energy conversion.