Removal of Azo Dye Calcon Using Polyaniline Films Electrodeposited on SnO2 Substrate

In order to find simple, effective and economical methods for dye adsorption, the present work aims at studying the adsorption efficiency of an azo dye “Calcon’’ by polyaniline (PA) films prepared by the electrochemical method. The characterization of these films by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–visible spectrophotometer showing an amorphous fibrillary structure of the PA electrodeposited. To find the best conditions for adsorption of Calcon dye, the effect of pH, hydrogen peroxide, contact time and the initial Calcon concentration were studied. These experiments showcased the possibility of increasing the adsorption capacity from 42% to 54% changing pH from 9 to 3. This value increases to 98.6% by the addition of hydrogen peroxide. On the other hand, the effect of Calcon concentration was studied from 15 to 50 mg/L, the results indicated that the discoloration of Calcon dye decreases with the increase of the dye concentration. However, Kinetics and isotherm studies have shown that the adsorption reaction follows the pseudo-second-order model, the adsorption process follows the Langmuir isotherm model, and the PA electrodeposited has a monolayer adsorption capacity of 606mg/g which is considerably high compared to all polyaniline forms prepared chemically.