Study on the UV Protection and Photocatalytic Activity of Cu 2+ and Fe 3+ Doped TiO 2 Nanoparticles

High Resolution Image Download MS PowerPoint Slide Titanium dioxide (TiO 2 ) is a safe inorganic sunscreen that provides broad-spectrum ultraviolet (UV) protection. It is usually mixed with organic materials or directly applied to the protected area. However, the photocatalytic activity of TiO 2 can decompose organic substances upon UV light exposure, causing negative effects. To further extend the UV protection wavelength range of TiO 2 and reduce its photocatalytic activity, copper/iron sulfate was added to titanium tetraisopropoxide (as TiO 2 precursor) in isopropanol in the presence of hydrochloric acid (as catalyst), yielding Cu 2+ /Fe 3+ -doped TiO 2 nanoparticles. X-ray diffraction analysis revealed the anatase crystal phase in doped TiO 2 nanoparticles annealed at 100 and 400 °C, whereas annealing at 700 °C resulted in rutile phase formation. Doped TiO 2 nanoparticles annealed at 100 °C exhibited an average particle size of approximately 10 nm, and the particle size distribution remained below 100 nm even when annealed at 700 °C, suggesting that Cu 2+ /Fe 3+ inhibited the condensation and crystallization of TiO 2 . UV–Visible spectrophotometry analysis confirmed that Cu 2+ /Fe 3+ doping effectively reduced UV light transmittance and enhanced visible light blocking, achieving broad-spectrum light protection. Moreover, by adjusting the weight percentage of Cu 2+ or Fe 3+, doped TiO 2 nanoparticles annealed at 100 °C, 400 °C, or 700 °C demonstrated reduced photocatalytic activity, offering a considerable advantage for sunscreen applications containing organic materials.