Exfoliation and Restacking Route to Anatase-Layered Titanate Nanohybrid with Enhanced Photocatalytic Activity
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- 作者：Jin-Ho Choy ; Hyun-Cheol Lee ; Hyun Jung ; Hasuck Kim ; and Hankil Boo
- 刊名：Chemistry of Materials
- 出版年：2002
- 出版时间：June 2002
- 年：2002
- 卷：14
- 期：6
- 页码：2486 - 2491
- 全文大小：79K
- 年卷期：v.14,no.6(June 2002)
- ISSN：1520-5002
文摘
A new microporous TiO2-pillared layered titanate has been prepared by hybridizing theexfoliated titanate with the anatase TiO2 nanosol. The stable colloidal nano-sheet wasobtained by intercalating tetrabutylamine into the layered protonic titanate, HxTi2-x/4
x/4O4·H2O(x = 0.67), with a lepidocrocite-like structure. The colloidal suspension of exfoliated titanatesheets was mixed with the monodispersed anatase TiO2 nanosol solution prepared by thehydrolysis of titanium isopropoxide with acetylacetone. The obtained nanohybrid was heatedat 300 
C for 2 h in order to complete the grafting reaction of intercalated anatase TiO2nanosol on the interlayer surface of layered titanate. According to the X-ray diffractionanalysis and N2 adsorption-desorption isotherms, it was found that the TiO2-pillared layeredtitanate showed a pillar height of ~2 nm, a high surface area of ~460 m2/g, and a pore sizeof ~0.95 nm, indicating the formation of a microporous pillar structure. Its photocatalyticactivity was evaluated by measuring the total volume of H2 gas evolved during the irradiationof the catalyst suspensions in water. The H2 gas evolution was found to increase from thelayered titanate (cesium and protonic form) to the unsupported TiO2 (acac-TiO2) and theTiO2-pillared layered titanate, because the electron and hole recombination in the pillaredsystem is thought to be effectively suppressed because of electron transfer between guestand host. A marked enhancement in the activity by ca. 40 times was obtained for TiO2-pillared layered titanate compared to pristine compounds such as layered titanate andanatase TiO2 nanosol when Pt (0.3 wt %) was doped on the surface of the sample.
x/4O4·H2O(x = 0.67), with a lepidocrocite-like structure. The colloidal suspension of exfoliated titanatesheets was mixed with the monodispersed anatase TiO2 nanosol solution prepared by thehydrolysis of titanium isopropoxide with acetylacetone. The obtained nanohybrid was heatedat 300 C for 2 h in order to complete the grafting reaction of intercalated anatase TiO2nanosol on the interlayer surface of layered titanate. According to the X-ray diffractionanalysis and N2 adsorption-desorption isotherms, it was found that the TiO2-pillared layeredtitanate showed a pillar height of ~2 nm, a high surface area of ~460 m2/g, and a pore sizeof ~0.95 nm, indicating the formation of a microporous pillar structure. Its photocatalyticactivity was evaluated by measuring the total volume of H2 gas evolved during the irradiationof the catalyst suspensions in water. The H2 gas evolution was found to increase from thelayered titanate (cesium and protonic form) to the unsupported TiO2 (acac-TiO2) and theTiO2-pillared layered titanate, because the electron and hole recombination in the pillaredsystem is thought to be effectively suppressed because of electron transfer between guestand host. A marked enhancement in the activity by ca. 40 times was obtained for TiO2-pillared layered titanate compared to pristine compounds such as layered titanate andanatase TiO2 nanosol when Pt (0.3 wt %) was doped on the surface of the sample.