Heterogeneous photocatalytic degradation of anionic dye on polyaniline/microcrystalline cellulose composite

The development of novel polymeric composites, especially those based on conductive polymers has attracted a considerable attention due to their applications in a wide range of fields. This study focuses on one of these biocomposites based on polyaniline Pani and a biopolymer (microcrystalline cellulose MCC), synthesized by in-situ polymerization of aniline using ammonium persulfate (APS) as oxidant at room temperature. Firstly, different amounts of MCC were dispersed in HCl solution with aniline monomer under stirring. Then a mixture of APS/HCl solution was introduced into the first aniline-MCC-HCl mixture. The obtained materials as well as Pani and MCC were characterized using powder X-ray diffraction (XRD), Argon adsorption-desorption (BET/DFT), thermal analysis, fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thus, a correlation between interesting structural/textural/morphological data of these materials will be established. The results confirm the formation of Polyaniline-MCC composite under well determined conditions which has a more compact homogeneous morphology and a higher thermal stability than those of Pani and MCC. Furthermore, these materials are used for the catalytic degradation of toxic anionic dye namely Methyl Orange (MO) from aqueous media under UV light irradiation. The optimum values were 0.1 g L- 1 of photocatalyst, 30 ppm of MO solution, and pH solution of 5.6, which allowed reaching 97% within 70 min with high stability after four continuous runs. The photodegradation kinetics of MO onto composite followed the pseudo-first order model.