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, TEM, 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 nm. The Cu-doped rutile TiO2 had new emission peak at 448 nm indicating the decrease of the bandgap energy of rutile TiO2. It exhibited an absorption edge at 480–490 nm longer than that for rutile TiO2 powder and led to a two times faster degradation of 4-cholorophenol.