碳-银共修饰的双晶介孔二氧化钛及其可见光催化活性

doi:10.15541/jim20140355

摘要/Abstract

摘要：

实验合成了一种具有锐钛矿和金红石双晶相骨架的介孔二氧化钛(meso-TiO₂), 通过碳和银纳米粒子修饰分别制备了碳掺杂(C-meso-TiO₂)、银纳米颗粒负载(Ag-meso-TiO₂)以及碳和银共修饰(Ag-C-meso-TiO₂)的双晶介孔二氧化钛, 然后通过其在可见光(波长>420 nm)下的亚甲基蓝(MB)水溶液的降解实验测试了样品的可见光催化活性。实验结果显示4种双晶介孔材料的可见光催化活性均明显优于商业锐钛矿二氧化钛纳米颗粒。由于杂质碳的带隙窄化作用和银纳米颗粒的表面等离子共振造成的电子转移, Ag-C-meso-TiO₂展现出最优的可见光催化活性, 在180 min可见光照射后, 其MB降解率达到65%, 而同样条件下商业二氧化钛纳米粒子的MB降解率仅为7%。

关键词: 可见光, 光催化活性, 双晶, 介孔二氧化钛, 银, 碳

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

中图分类号:

O644

陆强, 张智博, 董长青, 张晓媛, 崔方明. 碳-银共修饰的双晶介孔二氧化钛及其可见光催化活性[J]. 无机材料学报, 2014, 29(12): 1333-1338.

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.

图/表 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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