Enhanced Photochemical Response of TiO2/CdSe Heterostructured Nanowires

High-density single-crystalline TiO 2 nanowires (∼50 nm diam) were successfully grown on Ti substrates by chemical vapor deposition at a low temperature of 700 °C and within a remarkably short time period of 5 min. They were combined with CdSe nanocrystals (∼5 nm diam) to form TiO 2 /CdSe heterotructured nanowires by overcoating the nanowires with the CdSe-containing solution and subsequent annealing at 600 °C. The TiO 2 /CdSe nanowires showed uniformly distributed CdSe nanocrystals, and high crystallinity of rutile and wurtzite from the TiO 2 and the CdSe, respectively. Owing to the heterostructure of the TiO 2 /CdSe, they demonstrate almost full visible-range light absorption and thus enhanced photocatalytic activity by charge separation via electron and hole transfer between the CdSe and the TiO 2 .