Enhanced Photocatalytic Degradation of Congo Red Dye Using Green-Synthesized TiO₂ and PANI/TiO₂ with Papaya Leaf as Bio-Reduction

This study uses the green synthesis method to investigate the photocatalytic properties of TiO2 nanoparticles (NPs) and PANI/TiO2 nanocomposites (NCs). The in-situ polymerization method used the papaya leaf extract as a reducing agent. TiO2 NPs have a particle size of 56 nm and a band gap of 2.46 eV, while PANI/TiO2 NCs have a particle size of 44 nm and a band gap of 2.06 eV. The performance of TiO2 NPs and PANI/TiO2 NCs as semiconductor-based photocatalysis was evaluated using Congo red dye degradation. The results showed that PANI/TiO2 NCs have better photocatalytic performance with a Congo red dye degradation rate of 97.12 %, higher than TiO2 nanoparticles (95.52 %). This enhanced performance can contribute to the synergistic effect between the TiO2 and PANI, leading to improved charge separation and reduced recombination. HIGHLIGHTS TiO2 nanoparticles made from green synthesis using papaya leaf bio-reduction. TiO2 has an anatase crystal structure, a particle size of 56 nm, and a band gap energy of 2.46 eV. PANI/TiO2 nanocomposites were synthesized using in-situ polymerization and had a particle size of 44 nm with a band gap energy of 2.06 eV. PANI/TiO2 NCs have a higher degradation rate towards Congo red dye than TiO2 GRAPHICAL ABSTRACT