Photocatalytic degradation of organic pollutants in water: Application of TiO<sub>2</sub>-based nanocomposites

Organic pollutants represent a major environmental and human health concern due to water pollution. Addressing water pollution through sustainable and eco-friendly technologies is crucial for environmental preservation and public health. In this study, TiO₂-based nanocomposites' photocatalytic performance is studied for the degeneration of methylene blue (MB), phenol, and rhodamine B (RhB) to overcome the drawbacks of conventional water treatment methods. Methods of doping and co-catalyst enhancement of Titanium Dioxide (TiO₂)- based nanocomposites enhanced photocatalytic efficiency. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Ultraviolet-Visible Spectroscopy (UV-Vis) results were employed to distinguish the composites. Pollutant solution degradation was evaluated using photocatalytic degradation under UV and visible light, with degradation efficiencies evaluated over multiple cycles. The photocatalytic degradation of MB (88.7%), RhB (85.4%), and phenol (83.2%) were much higher for TiO₂-X composites than pristine TiO₂ and other doped TiO₂ variants. Kinetic analysis based on the Langmuir Hinshelwood model revealed an optimal rate constant of 0.015 min⁻¹ (R² = 0.98) for MB and RhB degradation, which was consistent with adsorption-limited reactions. The composites showed excellent stability and reusability, with over 85% of the initial catalytic activity being retained after five cycles. Enhanced photocatalytic performance for degradation of organic pollutants was achieved with TiO₂ based nanocomposites, providing a sustainable solution to water treatment. Future work will be towards optimizing synthesis methods as well as improving the photocatalytic activity under real-world conditions such as exposure to natural sunlight. TiO₂-based nanocomposites represent a sustainable solution for water treatment, offering high efficiency, long-term stability, and eco-friendly remediation of persistent organic pollutants.