Fabrication and Photocatalytic Activity of Pt-Inserted Titania Nanotubes
LI Hai-long1,LUO Wu-lin1,TIAN Wen-yu1,CHEN Tao1,LI Chun1,SUN Mao1,ZHU Di1, LIU Ran-ran1, ZHAO Yu-liang2, LIU Chun-li1*
1. Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 2. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
Abstract：Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticals in NaOH solution at 110 ℃ for 24 hours. After drying in aceton for 36 h, the TNTs were under vacuum drying for 24 h at room temperature. The Pt-inserted titania nanotubes (Pt/TNTs) were obtained by filling H2PtCl6 ethanol solution into the TNTs after vacuum drying. The characterizations of the as-synthesized samples were confirmed by TEM, XRD, and UV-Vis. The photocatalytic activity of the Pt/TNTs was investigated by photo-induced decomposition of methyl orange(MO)under the main 365 nm UV-light. In order to comparison, the photocatalytic activity of both the rutile-phase TiO2 nanoparticles and pure TNTs were also investigated at the same time under the same experimental conditions. The TEM images show that the TNTs are hollow, a few hundred nanometers long, and the inner/outer diameter is about 6/10 nm. The crystal structure of TNTs is H2Ti2O5·H2O with a little Na. Both the shape and the crystalline of the TNTs are not changed after the modification. The oval or round Pt0 nanoparticals, about 3 nm in diameter, are found only in the nanotubes. Pt/TNTs exhibit enhanced absorption at the visible range in the UV-Vis spectra and its start absorption band edge(λ0≈457 nm)is obviously redshifted compared to the rutile-phase TiO2 nanoparticals and pure TNTs. The Pt nanoparticles are found to significantly enhance the photocatalytic activity of TNTs. Pt/TNTs are demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both the rutile-phase TiO2 nanoparticals and pure TNTs. After irradiation for 60 min, the photocatalysis decomposition rate of MO in rutile-phase TiO2 nanoparticals, TNTs and Pt/TNTs are 46.8%，57.2% and 84.6% respectively.
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