Encapsulation of Zn–Fe layered double hydroxide on activated carbon and its litheness in tuning anionic and rhoda dyes through adsorption mechanism

Abstract

AbstractA flexible layered double hydroxide (LDH) composite of zinc and iron was encapsulated on orange peel activated carbon (Zn–Fe LDH EAC) surface by coprecipitation method to study the adsorption properties of acid blue (AB) and rhodamine B (RhB) dyes from water. Activated carbon was employed as a structure retaining agent as well as a supporting material for Zn and Fe hydroxides. The Zn–Fe hydroxides were introduced on activated carbon surfaces to study the effective removal of toxic AB and RhB dyes and their interaction mechanisms with composite surface. Various characterization techniques such as Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), energy‐dispersive X‐ray (EDAX), Brunauer–Emmett–Teller (BET) and scanning electron microscope (SEM) were used to analyse the fabricated and dye adsorbed composite. The adsorption experiments were carried out by varying different parameters such as contact time, dosage, pH and initial dye concentration. The fabricated composite exhibited increased adsorption density for both the dyes than the other developed hybrids. The Freundlich adsorption isotherm was found to be the better fit data than the Langmuir isotherm. The maximum adsorption of AB and RhB dyes on the adsorbent was 98.4% and 96.2% respectively. The high adsorption efficiency of Zn–Fe LDH Encapsulated Activated Carbon composite was due to the electrostatic attraction between zinc‐ferric hydroxide particles with AB and RhB and also the hydrogen bonding between Zn–Fe LDH EAC composite with AB and RhB dyes, during the adsorption process.