Biomass-based N-TiO2 composites for polyvinylchloride nano plastic photodegradation

Plastic pollution of the environment and water is a persistent global concern. Microplastic contamination has impacted aquatic environments, demanding the development of efficient remediation techniques to address this issue. In this work, N-TiO 2 –supported corncob activated (ZnCl 2 ) carbon (CCAC/N-TiO 2 ) composites (CT13) (CT11), and (CT31) were synthesized through a simple wet-impregnation approach. The prepared composite materials were characterized using Fourier transform infrared (FTIR) spectroscopy, XRD (X-ray diffraction), SEM (Scanning electron microscopy), EDS (Electron dispersive spectroscopy), XPS (X-ray photoelectron spectroscopy), thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, UV-visible spectroscopy and Dynamic Light Scattering (DLS) techniques. Tauc’s method was applied to evaluate the optical band gap, and the results indicated that the composite material’s spectral response extended into the visible-light region, accompanied by a significant reduction in band gap energy. The removal performance of the CCAC/N-TiO 2 composites toward PVC-NPs was systematically evaluated under different pH conditions (4, 7, and 10), varying contact times, and various light conditions. CT13 composite demonstrated exceptional performance, achieving a 94% degradation efficiency after 180 min of exposure to tungsten light. The removal of PVC-NPs was determined to occur via a photocatalytic pathway and was confirmed by quenching experiments. Additionally, SEM, FTIR, DLS, and fluorescence microscopy verified the presence of PVC-NPs on the composite surfaces under both dark and light conditions. The major photodegradation products were identified using gas chromatography-mass spectrometry (GC-MS). The addition of CCAC to N-TiO 2 significantly improved its ability to remove PVC-NPs. This is because the CCAC addition increased the number of active sites for adsorption. The CT13 composite’s surface attracts and captures the PVC-NPs through a variety of interactions, including hydrophobic interactions, electrostatic attractions, π-π interactions, halogen bonding, and hydrogen bonding. This strong adsorption increases the number of available reaction sites, which in turn boosts the photocatalytic removal of the PVC-NPs. This study sheds light on the use of biomass-derived materials for water purification, providing a long-term solution to pollution and agricultural waste issues.