Antibacterial and solar-driven photocatalytic activities of Co_xSn_1−xO_2−δ nanoparticles for wastewater treatment

Transition metal doped nanoparticles have potential for photodegradation, antibacterial activity, and water splitting. Co-doped SnO₂ nanoparticles (Co_xSn_1−xO_2−δ: x = 0–7%) with an average diameter of ≈ 32 nm are successfully synthesized using the coprecipitation method. The structural properties are investigated using an X-ray diffractometer (XRD) that shows tetragonal structure of the nanoparticles. Microstrain and average crystallite size of the nanoparticles are investigated using different XRD models. It is observed that 7% Co-doping reduces the optical bandgap down to 17% (3.04 eV). The nanoparticles show 75% photodegradation of methylene blue dye under sunlight exposure, and enhance antibacterial activity against both gram-positive and gram-negative bacteria. These results may provide pathways to utilize Co_xSn_1−xO_2−δ nanoparticles as efficient photocatalysts, antibacterial agents for industrial wastewater treatment, and water-splitting applications as well.