I missed this one in my previous overview of Chem. Mater. Some nice zinc and titanium spectra courtesy of Brad Chmelka.
Chem. Mater., 18 (26), 6345 -6351, 2006. 10.1021/cm0621693 S0897-4756(06)02169-7 Web
Hierarchically Porous Rutile Titania: Harnessing Spontaneous Compositional Change in Mixed-Metal Oxides
Eric S. Toberer, Jan D. Epping, Bradley F. Chmelka,* and Ram Seshadri*
Materials Department and Materials Research Laboratory and Department of Chemical Engineering, University of California, Santa Barbara, California 93106
Abstract: 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.