dSe/TiO2纳米管阵列同轴异质结的制备及其光电特性研究

he under-potential deposition (UPD) of Cd and Se elements on TiO2 nanotubes array substrate is studied. CdSe, a kind of narrowband gap semiconductor compound, is successfully deposited onto the walls of the highly structured and orderly TiO2 nanotubes array using a combination of UPD and co-deposition at a suitable potential. FESEM，XRD，EDAX and TEM analyses show that CdSe/TiO2 nanotubes array with coaxial heterojunction structure has been formed. The photoelectrochemical properties of the resulting films with the CdSe/TiO2 nanotube-array coaxial heterojunction are discussed. The results show that the maximum photoconversion effciency can be obtained for the sample with the sensitization layer using the deposition time of 7 h. In addition, the effect of annealing atmosphere on the photoactivity of as-prepared samples also has been investigated. It suggests that the annealing in nitrogen atmosphere can introduce the N atoms to TiO2 lattice, to a certain extent, is conducive to the improvement of photoactivity, however, the efficacy tends to decline in the wake of the increasing deposition time.