Fig. 7: Structural features and anion-exchange performance of the cationic MOF SCU-103. | npj Clean Water

Fig. 7: Structural features and anion-exchange performance of the cationic MOF SCU-103.

From: Advancing wastewater treatment with green and scalable metal–organic frameworks: from synthetic strategies to real-world deployment

Fig. 7

a Structural configuration and porosity of the cationic MOF SCU-103: (a) The Ni2+ centre adopts an octahedral coordination, each bonded to six nitrogen atoms from tridentate tipa ligands. b View of the framework’s 2D layers arranged in an ABC stacking pattern, creating periodic concave–convex morphology. c Close-up showing bowl-like cavities formed by the interlocking of adjacent layers, providing confined spaces for ion capture. d Open channels connecting the cavities, enabling diffusion of guest species throughout the porous matrix. (b) Sorption kinetics and selectivity of SCU-103: (a) UV–Vis spectra tracking the rapid decline of 99TcO4− absorbance at 290 nm, indicating swift anion removal. b Kinetic profiles showing > 90% uptake within minutes, confirming the fast anion-exchange process for both 99TcO4 and its surrogate ReO4−. c Langmuir-fitted adsorption isotherm revealing a high ReO4− uptake capacity of 318 mg/g. (d) High selectivity of SCU-103 for ReO4− in the presence of various competing anions. e−f Retention of uptake efficiency even under large excesses of NO3− and SO42−, emphasizing SCU-103’s strong anion preference under competitive conditions. Reproduced from ref. 99. Copyright 2020, Springer Nature.

Back to article page