Autor: |
S. Toberer, Eric, D. Epping, Jan, F. Chmelka, Bradley, Seshadri, Ram |
Zdroj: |
Chemistry of Materials; December 2006, Vol. 18 Issue: 26 p6345-6351, 7p |
Abstrakt: |
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 length scales of porosity are present in the porous medium. To this end, we have developed a route to hierarchically porous rutile titania that obviates the need for preformed or preassembled structure-directing agents. The preparation involves the successive leaching of phases and components from a dense composite of wurtzite ZnO and inverse spinel Zn2TiO4. The resulting monoliths are composed of grains of highly crystalline rutile titania and possess a hierarchy of interconnected pores with length scales of 5 m and 100 nm. Ex situ solid-state 67Zn and 47,49Ti NMR has helped probe local environments around these elements in both the mixed and pure crystalline materials that are formed during the leaching processes. |
Databáze: |
Supplemental Index |
Externí odkaz: |
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