The photocatalytic activity of 2.5 wt% Cu-doped TiO2 nano powders synthesized by mechanical alloying

In order to effectively utilize visible light, nano-sized Cu-doped TiO2 powders were prepared by mechanical alloying and were characterized by XRD, TEN4. DRS and photoluminescence (PL) spectra. Their photocatlytic activity was measured for 4-chlorophenol photodegradation. The results showed that 2.5 wt% of Cu element entered uniformly into the rutile TiO2 lattice with the average grain size less than 15 run. The Cu-doped rutile TiO2 had new emission peak at 448 nin indicating the decrease of the bandgap energy of rutile TiO2. It exhibited an absorption edge at 480-4,90 nm longer than that for rutile TiO2 powder and led to a two times faster degradation of 4-cholorophenol. (c) 2005 Elsevier B.V. All rights reserved.