Mesoporous Fe–Al-doped cellulose for the efficient removal of reactive dyes

Abstract

A highly efficient mesoporous bimetallic cellulose composite has been prepared by the simultaneous precipitation of Fe and Al metal solutions in a cellulose matrix. This Fe–Al doped cellulose (FADC) was characterized using XRD, FT-IR, SEM, EDAX, BET, and pH_PZC. It was used for the removal of two reactive dyes namely Reactive red 21 (RR21) and Reactive blue 19 (RB19) by a batch adsorption technique. The batch experiments were carried out to optimize the various operational parameters. The adsorption isotherm study showed that the data fitted to the Langmuir isotherm with a monolayer adsorption capacity of 117.86 mg g⁻¹ for RR21 dye and 95.62 mg g⁻¹ for RB19 dye. The pseudo-second-order model was fitted well while the mechanism of adsorption was deduced using the Weber–Morris model of intraparticle diffusion. Adsorption thermodynamics calculations revealed that the mechanism of adsorption is impulsive and driven by negative enthalpy change.