The antibacterial and photocatalytic properties of copper and tin doped titanium dioxide nanoparticles for the nano remediation of pesticide residues in soil

In this study, we synthesized copper and tin doped TiO₂ nanoparticles (NPs) (Cu-Sn-TiO₂) using a precipitation method and investigated their potential for nanoremediation of pesticide residues in soil. To characterize the physicochemical properties of the Cu-Sn-TiO₂ NPs, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were used. To assess their antibacterial activity against Escherichia coli and Staphylococcus aureus, we measured bacterial growth inhibition and bacterial membrane damage. We also used simulated solar irradiation to test their photocatalytic degradation of two commonly used pesticides, tebuconazole and trifloxystrobin soils. Cu-Sn-TiO₂ NPs outperformed pure TiO₂ in terms of visible light absorption, electron-hole recombination, antibacterial and photocatalytic performance. For both copper and tin, 0.01% was determined to be the ideal doping concentration. Within 20 hours, the Cu-Sn-TiO₂ NPs degraded tebuconazole and trifloxystrobin in soils by more than 50%. The acquired samples were quantified using validated UFLC with PDA detection. Kinetic parameters such as rate constant (k) and DT50 were calculated using pesticide residue dissipation data. After 20 hours of exposure, the Cu-Sn-TiO₂ NPs demonstrated significant antibacterial activity, reducing bacterial viability by more than 70%. Based on the formation of reactive oxygen species and the disruption of the bacterial membrane, the mechanism of the antibacterial and photocatalytic action of the Cu-Sn-TiO₂ NPs was discussed. The agricultural and environmental sectors may benefit from the Cu-Sn-TiO₂ NPs promising potential for the nanoremediation of pesticide residues in soils.