Multiscale Mechanistic Study of the Adsorption of Methyl Orange on the External Surface of Layered Double Hydroxide

Abstract

The molecular mechanism of Methyl Orange (MO) dye adsorption on the external surface of Mg2Al–CO3 layered double hydroxide (LDH) was investigated by combining adsorption isotherms, X-ray diffraction, and infrared (IR) and Raman spectroscopies coupled to DFT calculations. The vibrational dynamic behavior upon adsorption and the molecular surface organization were correlated with the adsorption isotherm revealing a four-domain uptake mechanism. The peculiar high adsorption capacity of LDH toward MO was explained by the surface-promoted dye aggregation over the external surface of particles.