Extended Data Fig. 2: Ion selectivity simulation.
From: Advancing osmotic power generation by covalent organic framework monolayer
a, The simulated 2D domain for PNP model. The pore length and diameter of each pore is 0.6 nm and 2 nm, respectively. In all the simulations, the concentration and potential of the central pore are used to calculate the current. b, c, Calculated steady-state concentration distribution of K+ (b) and Cl− (c) near ZnTPP-COF monolayer membrane with a surface charge density of 4.1 mC m-2 under a salt gradient of 10 mM/0.1 mM, respectively. The higher concentration of Cl− (counter-ions) compared with that of K+ (co-ions) in the whole pore region suggests the anion selectivity of the membrane. d, An electrostatic potential under salt gradient of 10 mM/0.1 mM builds up along the salinity gradient direction, owing to the selective transport of anions across the membrane.
