Novel glauconite nanorods (GNRs) were synthesized by
the sonication-induced
chemical expansion and scrolling process of natural glauconite. The
synthetic nanostructure was characterized by different analytical
techniques as a superior adsorbent for the malachite green dye (MG).
The synthetic GNRs were detected as porous nanorods with an average
length of 150 nm to 5 μm, an average diameter of 25 to 200 nm,
and a specific surface area of 123.7 m
2
/g. As an adsorbent
for MG, the synthetic GNRs showed superior uptake capacity up to 1265.6
mg/g at the saturation stage, which is higher than most of the recently
developed highly adsorbent dyes. The adsorption behavior and mechanistic
properties were depicted by using modern and traditional equilibrium
modeling. The kinetic assumption of the pseudo-first-order model (
R
2
> 0.94) and the classic isotherm of the
Langmuir
equilibrium model (
R
2
> 0.97) were
used
to describe the adsorption reactions. The steric investigation demonstrates
that each active site on the surface of GNRs can adsorb up to three
MG molecules (
n
= 2.19–2.48) in vertical orientation
involving multimolecular mechanisms. Also, the determined active site
density (577.89 mg/g) demonstrates the enrichment of the surface of
GNRs with numerous adsorption receptors with strong affinity for the
MG dye. The energetic study, including Gaussian energy (6.27–7.97
kJ/mol) and adsorption energy (9.45–10.43 kJ/mol), revealed
that GNRs had physically adsorbed the dye, which might involve electrostatic
attraction, hydrogen bonding, van der Waals forces, and dipole forces.
The internal energy, enthalpy, and entropy determined the exothermic
and spontaneous uptake of MG.