Photocatalytic ability of coatings based on carboxylated polyaniline@multi-walled carbon nanotubes dispersions deposited onto microfibrous cellulose substrate for degradation of MB dye

The demand for sustainable, multifunctional materials in photocatalysis, flexible electronics and biomedical applications has driven the exploration of novel composite systems. In this study, we report a novel multifunctional composite material prepared by integrating in situ synthesized carboxylated polyaniline (c-PANI) in the presence of multi-walled carbon nanotubes (MWCNTs) with the use of formic acid as reaction media. The resultant stable dispersions in volatile solvent were further used for an easy and affordable impregnation deposition onto a cellulose filter paper substrate in order to obtain flexible and electron-conductive composite scaffolds with variable CNTs content. The structural, morphological and thermal properties of the nanocomposite cellulosic substrates were characterized using FT-IR and XPS spectroscopy, SEM, DLS and TG analysis, confirming the successful integration of c-PANI@MWCNTs onto the surface of cellulose matrix. The prepared c-PANI@MWCNTs/cellulose composites are tested in the reaction of photocatalytic degradation of Methylene Blue (MB) dye under UV light. The photocatalytic results determined that c-PANI@MWCNTs impregnated cellulose substrates possess enhanced photocatalytic efficiency (up to 83% MB dye degree of degradation) in comparison with the pure c-PANI. The improved photocatalytic ability of c-PANI/MWCNTs composite materials could be due to the synergistic effect of the carbon nanotubes and conductive PANI matrix, which favor charge transport and facilitate interfacial electron charge transfer.