The effect of morphology of polyaniline on photodegradation of reactive black 5 dyes

• Main Authors: Khor, Shu-Hui, Lee, Michelle Li-Yen, Basirun, Wan Jefrey, Juan, Joon-Ching, Phang, Sook-Wai
• Format: Article
• Published: Springer Verlag (Germany) 2024
• Subjects: Q Science (General); QD Chemistry
• Online Access: http://eprints.um.edu.my/45969/

Photocatalysis is widely used for wastewater treatment as it is environmentally friendly through elimination of harmful organic compounds by mineralizing it to carbon dioxide and water under light illumination. Morphology control of polyaniline (PANI) is thought to affect the specific surface area and conductivity of the composites which subsequently contribute toward the photodegradation performance. In this research study, a binary system of PANI-TiO2 photocatalyst with different morphologies including nanotubes, nanofibers, nanospheres, star micro-/nanostructure and leaf micro-/nanostructure was fabricated for photodegradation of reactive black 5 (RB5) dye under visible light irradiation. Based on the characterization, PANI-TiO2 composites managed to reduce band gap to 2.68-2.72 eV which is proven to be easily activated under visible light region. Meanwhile, the photoluminescence analysis showed that the electron hole (e-h+) recombination was also retarded to provide opportunity for more radical generation. The PANI nanotubes (NT-PANI-TiO2) demonstrate highest photodegradation efficiency of 54.4% after 2 h. Interestingly, PANI leaf micro-/nanostructure (L-PANI-TiO2) shows highest increment of 35.3% of L-PANI to 48.8% of L-PANI-TiO2. This demonstrates the effectiveness of PANI nanotubes and leaf structures along with TiO2 as potential photocatalyst composite.