Visible-Light-Driven Cd–Ti–Fe Nanocomposites for Efficient Degradation of Emerging Pollutants and Optimum Antibacterial Activity

Organic contaminants represent a persistent threat to aquatic ecosystems and public health due to their stability and toxicity. Herein, a Cd–Ti–Fe nanocomposite photocatalyst was synthesized via a facile co-precipitation route and investigated for the degradation of representative organic pollutants, namely Congo Red (CR), Brilliant Green (BG), and p -nitrophenol (PNP). The structural and physicochemical properties of the nanocomposite were systematically characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), and UV–visible diffuse reflectance spectroscopy. Optical analysis revealed a band gap of 2.94 eV derived from the Tauc plot, indicating strong responsiveness under visible-light irradiation. Under optimized photocatalytic conditions, the Cd–Ti–Fe nanocomposite achieved degradation efficiencies of 98.00% for CR, 96.40% for BG, and 94.89% for PNP. The corresponding quantum yields were 7.68 × 10⁻³, 1.05 × 10⁻², and 3.58 × 10⁻², with reaction rates of 6.1, 2.0, and 41 µmol g⁻¹ h⁻¹, respectively. Kinetic analysis revealed superior fitting to the pseudo-first-order (PFO) model for all pollutants, indicating a surface reaction-limited process. Moreover, the nanocomposite exhibited pronounced antibacterial activity against Escherichia coli and Staphylococcus aureus . Collectively, these results highlight the potential of the Cd–Ti–Fe nanocomposite as an efficient multifunctional material for simultaneous photocatalytic degradation of organic pollutants and antimicrobial treatment in wastewater remediation.