Water Pollution Remediation: Efficient Photocatalytic Degradation of Direct Yellow 12 Dye Using Poly(o-ethylaniline)/TiO2/rGO Nanocomposites

Abstract

Water pollution has become a global issue due to growing industrial activities, particularly the release of toxic dyes in textile wastewater. Therefore, water treatment is inevitable to conserve and reuse the wastewater. In our study, a photocatalytic technique was designed to degrade the commonly used direct yellow 12 (DY-12) dye present in aqueous media using polymeric composite materials based on poly(o-ethylaniline)/titanium dioxide/reduced graphene oxide (POEA/TiO₂/rGO). The composites were analyzed by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) for the confirmation of the composition and the structural features, respectively. Furthermore, scanning electron microscopy (SEM) was employed to observe the surface morphology of the materials, while the photocatalytic activity of the composites was evaluated for the degradation of DY-12 dye under ultraviolet (UV) irradiation. Then, the factors affecting the photocatalytic activity (pH = 2, dye concentration = 100 ppm, catalyst dose = 500 mg/L, oxidant concentration = 15 g/L, temperature 60 °C, and irradiation time = 60 min) were optimized which achieved up to 98% removal of the target dye by the POEA/TiO₂/rGO_25% catalyst. After photocatalytic degradation, total organic carbon (TOC), chemical oxygen demand (COD), and FTIR analysis were performed to ensure the removal of the dye. Moreover, kinetic studies demonstrated that the degradation process followed the first-order rate mechanism.