Photocatalytic and Antibacterial Properties of Doped TiO 2 Nanopowders Synthesized by Sol-Gel Method.

For environmental applications, nanosized TiO ₂ -based materials are known as the most important photocatalyst and are intensively studied for their advantages such as their higher activity, lower price, and chemical and photoresist properties. Zn or Cu doped TiO ₂ nanoparticles with anatase crystalline structure were synthesized by sol-gel process. Titanium (IV) butoxide was used as a TiO ₂ precursor, with parental alcohol as a solvent, and a hydrolysing agent (ammonia-containing water) was added to obtain a solution with pH 10. The gels were characterized by TG/DTA analysis, SEM, and XPS. Based on TG/DTA results, the temperature of 500 °C was chosen for processing the powders in air. The structure of the samples thermally treated at 500 °C was analysed by XRD and the patterns show crystallization in a single phase of TiO ₂ (anatase). The surface of the samples and the oxidation states was investigated by XPS, confirming the presence of Ti, O, Zn and Cu. The antibacterial activity of the nanoparticle powder samples was verified using the gram-positive bacterium Staphylococcus aureus . The photocatalytic efficiency of the doped TiO ₂ nanopowders for degradation of methyl orange (MO) is here examined in order to evaluate the potential applications of these materials for environmental remediation.