Preparation and photocatalytic property of mesoporous ZnO/SnO sub(2) composite nanofibers

• Published in: Journal of alloys and compounds 2010-07, Vol.503 (1), p.103-110
• Main Authors: Liu, Ruilai, Huang, Yingxing, Xiao, Aihua, Liu, Haiqing
• Format: Article
• Language: English
• Subjects: Calcination; Nanofibers; Photocatalysis; Scanning electron microscopy; Tin dioxide; Tin oxides; Transmission electron microscopy; Zinc oxide
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2010.04.211

In this paper, we prepared mesoporous ZnO/SnO sub(2) composite nanofibers via the electrospinning technique using zinc acetate (Zn(OAc) sub(2)) and stannic chloride pentahydrate (SnCl sub(4) super(.5H) sub(2)) as precursors, cellulose acetate (CA) as the fiber template, and N,N-dimethylformamide (DMF)/acetone (1:1, v/v) as the co-solvent. The structure and morphology of composite nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS) and nitrogen adsorption-desorption isotherm analysis. TEM images showed that the mesoporous ZnO/SnO sub(2) composite nanofibers were composed of grain-like nanoparticles. The nanoparticles size increased with the increasing of the calcination temperature from 500 to 900 degree C. Moreover, the crystal phases, grain sizes, and band gap energy of the mesoporous ZnO/SnO sub(2) composite nanofibers were influenced by the molar ratio of Zn:Sn and the calcination temperatures. The photocatalytic activity of the mesoporous ZnO/SnO sub(2) composite nanofibers toward the decomposition of Rhodamine B (RhB) was investigated. It was found that the photocatalytic activity of the mesoporous ZnO/SnO sub(2) composite nanofibers was dependant on their surface areas, light utilization efficiency, and the separation of photogenerated electron/hole pairs. The maximum photocatalytic activity was shown for composite nanofibers with the molar ratio of Zn:Sn = 2:1 and calcination at 500 degree C for 5 h, more or less Zn:Sn ratios lowered the photocatalytic efficiency. A mechanism of the charge separation and photocatalytic reaction for the mesoporous ZnO/SnO sub(2) composite nanofibers was also presented.