Hierarchically Porous Rutile Titania: Harnessing Spontaneous Compositional Change in Mixed-Metal Oxides

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• 作者：Eric S. Toberer ; Jan D. Epping ; Bradley F. Chmelka ; Ram Seshadri
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：December 26, 2006
• 年：2006
• 卷：18
• 期：26
• 页码：6345 - 6351
• 全文大小：466K
• 年卷期：v.18,no.26(December 26, 2006)
• ISSN：1520-5002

文摘

In numerous applications involving fluid flow through a porous structure, performance improvements,such as better flow characteristics and increased fluid-solid contact, are obtained when multiple lengthscales of porosity are present in the porous medium. To this end, we have developed a route tohierarchically porous rutile titania that obviates the need for preformed or preassembled structure-directingagents. The preparation involves the successive leaching of phases and components from a dense compositeof wurtzite ZnO and inverse spinel Zn₂TiO₄. The resulting monoliths are composed of grains of highlycrystalline rutile titania and possess a hierarchy of interconnected pores with length scales of 5 s/entities/mgr.gif">m and100 nm. Ex situ solid-state ⁶⁷Zn and ^47,49Ti NMR has helped probe local environments around theseelements in both the mixed and pure crystalline materials that are formed during the leaching processes.