Enhanced Photocatalytic and Photokilling Activities of Cu-Doped TiO(2) Nanoparticles

In this work, metal-doped titanium dioxide (TiO(2)) was synthesised with the aim of improving photocatalytic degradation and antimicrobial activities; TiO(2) was doped with copper (Cu) ranging from 0.1 to 1.0 wt%. The physical and chemical properties of the Cu-doped TiO(2) nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), the Brunauer–Emmett–Teller method (BET) and diffuse reflection spectroscopy (DRS). The results revealed that the anatase phase of TiO(2) was maintained well in all the Cu-doped TiO(2) samples. No significant difference in the particle sizes or the specific surface areas was caused by increasing Cu doping. However, the band gap decreased continuously from 3.20 eV for undoped TiO(2) to 3.12 eV for 1.0 wt.% Cu-doped TiO(2). In addition, the 0.1 wt.% Cu-doped TiO(2) displayed a much greater photocatalytic degradation of methylene blue (MB) and excellent antibacterial ability for Escherichia coli (E. coli) compared to undoped TiO(2). On the other hand, the high Cu doping levels had negative impacts on the surface charge of nanoparticles and charge transfer for OH• generation, resulting in decreasing MB degradation and E. coli photokilling for 1.0 wt.% Cu-doped TiO(2).