Improved Visible-light Photocatalytic Activity of Bi-crystalline Mesoporous Titania Codoped with Carbon and Silver

doi:10.15541/jim20140355

Abstract

Abstract:

A bi-crystalline mesoporous titania (meso-TiO₂) with anatase and rutile composite nanocrystal frameworks was prepared and then modified by carbon doping (C-meso-TiO₂), silver nanoparticle loading (Ag-meso-TiO₂), and carbon-silver codoping (Ag-C-meso-TiO₂). The visible-light photocatalytic activities of the samples were evaluated by the degeneration of aqueous methylene blue (MB) solution under visible-light irradiation (wavelength >420 nm). The prepared bi-crystalline mesoporous samples showed obviously higher visible-light photocatalytic activity than that of the commercial anatase titania nanoparticles (NPs). Ag-C-meso-TiO₂ exhibited the highest visible-light photocatalytic activity which could be attributed to the band gap narrowed by the doped carbon and the plasmon electron transfer from Ag NPs to the titania matrix, and the corresponding MB degeneration rate reached 65% after 180 min visible-light irradiation while that of the commercial titania NPs just reached 7%.

Key words: visible-light, photocatalytic activity, bi-crystalline, mesoporous titania, silver, carbon

CLC Number:

O644

LU Qiang, ZHANG Zhi-Bo, DONG Chang-Qing, ZHANG Xiao-Yuan, CUI Fang-Ming. Improved Visible-light Photocatalytic Activity of Bi-crystalline Mesoporous Titania Codoped with Carbon and Silver[J]. Journal of Inorganic Materials, 2014, 29(12): 1333-1338.

Figures/Tables 6

Fig. 1 SAXRD pattern of the bi-crystalline meso-TiO2 after calcination

Fig. 2 TEM image (a) and EDS spectrum (b) of the bi-crystalline Ag-C-meso-TiO2

Fig. 3 WAXRD patterns of bi-crystalline meso-TiO2 (a) and Ag-C-meso-TiO2 (b)

Fig. 4 N2 adsorption-desorption isotherms of the bi-crystalline meso-TiO2 and Ag-C-meso-TiO2 The inset is the pore size distribution of the blank meso-TiO2

Fig. 5 UV-visible adsorption spectra of (a) the blank bi-cryst-alline meso-TiO2, (b) Ag-meso-TiO2 and (c) C-meso-TiO2 The insets are the curves of (αhν)1/2 against hν of the samples

Fig. 6 Visible-light photodegradation of aqueous MB solution by different titania samples. The data in the graph are averaged by five points and the offsets are less than 7% of the averaged data

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