Biosynthesis of Cu-doped TiO2 nanoparticles with Aloe vera extract for air purification and disinfection

The use of plant extracts for the synthesis of nanoparticles has attracted much attention due to its simplicity, environmental friendliness, and cost-effectiveness. This study synthesized titanium dioxide (TiO2) nanoparticles using Aloe vera and Salvia extracts. Its doping with copper was also investigated to reduce the electron/hole pair recombination rate and improve the photocatalytic activity of titania. Biosynthesized titania (TiO ₂ ) nanoparticles were characterized by X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). XRD reported the formation of crystals with sizes of 4–7 nm by the Scherrer method and 5–27 nm by the Williamson-Hall method. FE-SEM and TEM analysis showed the formation of spherical particles. Spectroscopic results showed that adding copper element reduced the band gap energy from 3.10 eV to 2.89 eV. These results increased the removal efficiency of suspended particles, Escherichia coli bacteria, and coronavirus by titania nanoparticles. Therefore, Cu-TiO ₂ nanoparticles biosynthesized with Aloe vera extract showed increased photocatalytic and antibacterial activity that can be used for air purification.