title: Luminescence and photocatalytic activity of ZnO nanocrystals: correlation between structure and property.
abstract: Low-dimensional ZnO nanocrystals with controlled size, aspect ratio, and oxygen defects (e.g., type and concentration) are successfully prepared through simple solvothermal and thermal treatment methods. The structure of the as-synthesized samples is characterized by XRD, N2 physical adsorption, TEM, and IR and XPS spectra. The results show that the aspect ratio and size of the as-synthesized ZnO nanocrystals increase with increasing [OH-]/[Zn2+]; the morphology evolves from nanorod to nanoparticle with an increase in the annealing temperature; the BET surface areas of the corresponding samples decrease during these processes, respectively; and different oxygen defects, which are likely to be oxygen vacancy (Vo**) and interstitial oxygen (Oi''), are formed in our experiments accordingly. With evolution of the structure, IR absorption bands and visible photoluminescence emission peaks of the synthesized ZnO nanocrystals shift and split, which is ascribed to the change of oxygen defects. In addition, it is found that the photocatalytic activity of the synthesized ZnO nanocrystals is mainly dependent on the type and concentration of oxygen defects. The relationship of structure-property and the possible photocatalytic mechanism are discussed in detail.
authors.affiliation: National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian, China.
authors.forename: Yuanhui
authors.initials: Y
authors.lastname: Zheng
authors.forename: Chongqi
authors.initials: C
authors.lastname: Chen
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhan
authors.forename: Xingyi
authors.initials: X
authors.lastname: Lin
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
authors.forename: Kemei
authors.initials: K
authors.lastname: Wei
authors.forename: Jiefang
authors.initials: J
authors.lastname: Zhu
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Zhu