Enhanced photochemical response of TiO₂ZCdSe heterostructured nanowires

High-density single-crystalline TiO₂ 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 TiO₂/CdSe nanowires showed uniformly distributed CdSe nanocrystals, and high crystallinity of rutile and wurtzite from the TiO₂ and the CdSe, respectively. Owing to the heterostructure of the TiO₂/ 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 TiO₂.