The optimization of leaf-structured polyaniline-titanium dioxide composite toward effective photodegradation of reactive black 5 dyes

Abstract

The discharge of toxic organic dye from textile industries causes concerning effects on aquatic life, and this raises the urgent need for an effective treatment method that can preserve the environment. Recently, photocatalysis has been widely studied due to its environmentally friendly nature in which hazardous organic compounds can be converted into carbon dioxide and water through solar energy. In this research, polyaniline (PANI) with a leaf micro/nanostructure (L-PANI) is used to form a composite with different weight % (wt %) of titanium dioxide (TiO₂) to be used as a photocatalyst toward the photodegradation of Reactive Black 5 (RB5) dyes. Based on the results, L-PANI with 5 wt %, 10 wt %, 20 wt %, and 30 wt % of TiO₂ showed photodegradation of 44.2%, 48.8%, 41.7%, and 35.5%, respectively toward RB5 dyes. The optimum photodegradation parameters were further studied using L-PANI-TiO₂ (10 wt %), and it was found that a photodegradation efficiency of 98.2% is achieved with 80 min of dark adsorption time, 180 min of light reaction time, 10 ppm of initial RB5 dye concentration, and 25 mg of photocatalyst. To achieve 100% photodegradation of RB5 dye, the light reaction time was extended to 210 mines, and the 10 ppm of RB5 dye was successfully photodegraded to 100% using 25 mg of L-PANI-TiO₂ (10 wt %) photocatalyst. This shows the potency of L-PANI-TiO₂ as an effective photocatalyst toward the photodegradation of RB5 dye.