Adsorption of rhodamine-B by polypyrrole Sn (IV) tungstophosphate nanocomposite cation exchanger: Kinetic-cum-thermodynamic investigations

Abstract

ABSTRACT Synthesis of an organic-inorganic polypyrrole Sn(IV) tungstophosphate (Ppy-SWP) nanocomposite cation exchanger is used to study the adsorption of Rhodamine B (RH-B) utilizing batch adsorption by in-situ chemical oxidative polymerization of pyrrole (Ppy) with Sn(IV) tungstophosphate (SWP). FT-IR, XRD, SEM, TEM, and TGA were used to examine the synthesized material’s structural, morphological, and chemical features, revealing the successful Ppy-SWP nanocomposite synthesis. The impact of several parameters, such as pH, adsorbent amount, contact time, and starting dye concentration on RH-B adsorption onto Ppy-SWP, was investigated. The ion exchange capacity (IEC) and maximum level of RH-B dye adsorbed onto Ppy-SWP were reported to be 2.7 meq/g and 209.13 mg/g respectively. Kinetic (pseudo-first order, pseudo-second order, and intraparticle diffusion) and isotherm (Langmuir, Freundlich, Temkin, and Redlich–Peterson) models were used to pick the ideal match for the adsorption data. The Langmuir and Redlich–Peterson isotherm models fit the adsorption data well, while the pseudo-second order model best describes the kinetics data of RH-B adsorption. According to the computed thermodynamic variables standard-free energy, enthalpy, and entropy, the RH-B adsorption onto the Ppy-SWP is a spontaneous, endothermic, and physical sorption process. Even after seven cycles, regeneration experiments revealed an efficiency of greater than 80%.