Adsorption behavior of metal–organic frameworks for methylene blue from aqueous solution

Synthesis, Structure, and Dye Adsorption Properties of a Nickel(II) Coordination Layer Built from d-Camphorate and Bispyridyl Ligands

“…On the other hand, the adsorption capacity of MyB on adsorbent 1 significantly increased as the initial dye concentration increased, suggesting favorable adsorption at high dye concentrations. To explore the adsorption kinetics precisely, the dynamics of adsorption were interpreted by a pseudo-second-order linear kinetic model [11,42,43], which can be expressed by Equation (3):…”

“…To explore the adsorption kinetics precisely, the dynamics of adsorption were interpreted by a pseudo-second-order linear kinetic model [11,42,43], which can be expressed by Equation (3):…”

“…The adsorption isotherm of the MyB was obtained at initial concentrations of 10-200 ppm on 1 at room temperature by plotting the Q e as a function of C e after adsorption ( Figure 6). The above-mentioned equilibrium data of 1 were firstly fitted to the Langmuir isotherm model ( Figure S6a) [11,46], which is derived on an assumption that an ideal monolayer adsorption process takes place at specific equivalent sites within the homogeneous adsorbent surface. The linear form of the Langmuir isotherm model equation is given by Equation (4):…”

“…However, this value shows 1 to be a good adsorbent to adsorb MyB from water when compared with traditional adsorbents such as activated charcoal. Graphene/β-cyclodextrin (GNS/β-CD) composite 580.4 [39] Further, a dimensionless separation factor RL derived from the initial concentration of dye (Ci, ppm) and Langmuir adsorption constant (KL, L•mg −1 ) can also be used to predict the favorability of an adsorption system, which is defined as Equation (5) [11,29]:…”

“…As observed, all the RL values ranging from 0 to 1.0 represent favorable adsorption of MyB over adsorbent 1 at the conditions being studied. The Freundlich isotherm model [11,47], which is an empirical equation used to imply multilayer adsorption on roughly heterogeneous adsorbent surfaces caused by the presence of different functional groups on the surface and several adsorbent-adsorbate interactions, was also tested to fit the equilibrium data of MyB adsorption isotherm ( Figure S6b). The linear form of the Freundlich isotherm model can be expressed by Equation (6): Graphene/β-cyclodextrin (GNS/β-CD) composite 580.4 [39] Further, a dimensionless separation factor R L derived from the initial concentration of dye (C i , ppm) and Langmuir adsorption constant (K L , L·mg −1 ) can also be used to predict the favorability of an adsorption system, which is defined as Equation (5) [11,29]:…”