Investigation of adsorptive properties of Ag2CO3-polyaniline composite for environmental pollution control

Abstract

In this research, the Ag2CO3-PANI composite was synthesized with a simple precipitation method and then used as an effective adsorbent for adsorption of Methylene Blue cationic dyes from aqueous solution. Characterization of the adsorbent was carried out using UV–visible diffuse reflectance spectroscopy (UV–Vis DRS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The various parameters such as pH, contact time, sorbent dosage, initial dye concentration, and dye solution temperature were investigated. The optimum photo-catalytic activity of Ag2CO3-PANI at a weight content of 50% PANI for the degradation of MB was almost 86% that is much higher than the pure Ag2CO3 and PANI. The results showed an efficient removal at pH 10.0, within 60 min, and by using 1 g L-1 Ag2CO3-PANI composite at the temperature of 32˚C. The kinetic and equilibrium data fit into pseudo-second-order kinetic (R2> 0.84) and Freundlich isotherm (R2> 0.99) models, respectively. Adsorption capacity (q0) calculated from Langmuir isotherm was found to be 55 mg/g. Thermodynamic studies indicated that the adsorption process was endothermic (ΔH°˃0). The adsorption/desorption experiments were carried out attaining regenerations of up to 97% from MB, using distilled water and 0.1N HCl. The composite indicated high efficiency adsorptive properties and high reusability.