Ultrasonic-assisted polyaniline-multiwall carbon nanotube photocatalyst for efficient photodegradation of organic pollutants

Abstract

Polyaniline (PANI) and multi-walled carbon nanotube (MWCNT) were used for synthesis of PANI/MWCNT nanocomposites (NCs) via ultrasonic method. The characterization of the PANI/MWCNT NCs were performed by Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet-visible spectroscopy, and field emission scanning electron microscope. The application and photostability of PANI/MWCNT NCs as recyclable photocatalysts for organic dyes removal, including methylene blue (MB), rhodamine B (RhB), and Methyl Orange (MO), were investigated in presence of ultraviolet (UV) light. Obtained results indicated that PANI/MWCNT NCs with 7 wt% MWCNT showed photodegradation efficiencies of 62.18%, 59.94%, and 98.39% compared to PANI standalone with efficiencies of 22.17%, 18.80%, and 79.80% for MB, RhB, and MO dyes within 45 min, respectively. The kinetic analysis demonstrated that photodegradation results were well fitted with the pseudo-second-order model. A comparison between the photodegradation and adsorption performance of PANI/MWCNT NCs were carried out to better understand the effectiveness of UV light irradiation on the dye removal. It was found that the synthesized NCs performed better under UV light irradiation in removing the organic dyes.