New Hybrid Adsorbents Based on Polyaniline and Polypyrrole with Silicon Dioxide: Synthesis, Characterization, Kinetics, Equilibrium, and Thermodynamic Studies for the Removal of 2,4-Dichlorophenol

In the current study, polyaniline and polypyrrole with silicon dioxide (PAni:PPy@SiO2) were combined to formulate a new adsorbent, which was examined using XRD, TEM, SEM, FTIR, TGA, and BET, and the adsorption kinetics were investigated by UV-vis spectroscopy. The optical band gap was also evaluated. The electrochemical behavior was investigated using cyclic voltammograms. Moreover, experimental conditions were used to evaluate the 2,4-dichlorophenol (2,4-DCP) adsorption based on the pH, temperature, reaction time, and initial concentration. The analytical isotherm data were determined by Langmuir, Freundlich, Temkin, Sips, and Redlich-Peterson models. For the analysis of the kinetic data, the pseudo-first- and -second-order models and the intraparticle diffusion model were investigated. It was found that this new adsorbent possessed the highest adsorption efficiency after several regeneration cycles. Furthermore, the thermodynamic parameters of adsorption, such as entropy (?S), enthalpy (?H), and standard Gibbs were measured. These results suggest that the PAni:PPy backbone can generally be better applied for the elimination of 2,4-dichlorophenol by appropriately dispersing it over the surface of suitable SiO2. This search provides a novel way to develop separable, high-performance adsorbents for adsorbing organic contamination from wastewater.

Automated summary

In this study, a new adsorbent, polyaniline and polypyrrole with silicon dioxide (PAni:PPy@SiO2), was developed and characterized using various techniques. The adsorption kinetics and optical properties were investigated, along with the electrochemical behavior. The adsorption of 2,4-dichlorophenol was evaluated under different conditions and analyzed using different models. The results indicate that the PAni:PPy@SiO2 adsorbent shows high efficiency in adsorbing organic contamination and can be regenerated for multiple cycles.