Fig. 11: Proposed mechanisms for dye adsorption on MOFs. | npj Clean Water

Fig. 11: Proposed mechanisms for dye adsorption on MOFs.

From: Analysis of microstructure properties of Ni-Fe MOFs and their influence on selective recognition of single and binary dye systems

Fig. 11

Fe-MOFs: Electrostatic attraction (Fe³⁺/Fe²⁺–EY⁻ –SO₃⁻), hydrogen bonding (-OH in Fe-MOFs– –C=O/–OH in EY), multilayer adsorption (following the Freundlich isotherm), chemisorption (Fe sites–EY functional groups). Ni-MOFs: π–π stacking (NR aromatic rings–Ni-MOFs conjugated structures), electrostatic attraction (negative Ni-MOFs–cationic NR), Ni²⁺–N/-NH₂ coordination, van der Waals stabilization. Ni/Fe (1:1) MOFs: Synergistic effects (Ni-Fe clusters), electrostatic attraction (Ni²⁺/Fe³⁺–AF⁻ –SO₃⁻), hydrogen bonding (–OH on MOFs–AF relevant groups), multilayer adsorption (mixed isotherm), chemisorption (Ni/Fe sites–AF active groups). Fe-MOFs are red, Ni-MOFs are blue, and Ni/Fe (1:1) MOFs are orange.

Back to article page