Mesoporous silica molecular sieve SBA-15 has been synthesized and incorporated with variable amounts of titanium via incipient-wetness impregnation with titanium isopropoxide in ethanol followed by calcination. Characterization by powder X-ray diffraction, nitrogen adsorption, X-ray photoelectron, Raman, and diffuse reflectance ultraviolet spectroscopies has been carried out to understand the chemical nature of the titanium. The results suggest that titanium is present in two distinct chemical forms and that their relative amounts depend on the titanium loading. At low titanium loading of 1 atom % relative to silicon, the titanium ions are monatomically dispersed and the pore size of SBA-15 is not altered. This isolated titanium species reaches a maximum concentration around 6 atom % relative to silicon. At higher titanium loading, titanium dioxide (anatase) is also formed. The materials with significant titanium dioxide formation have reduced pore diameters, which suggests that the titanium dioxide exists as a thin film anchored inside the mesopores of SBA-15. This new material may have potential as a novel catalyst.

X-ray photoelectron spectroscopy is used to analyse systematically a group of La 1−x Sr x -based mixedmetal perovskite-type oxides of interest in the development of oxygen separation membranes. Angleand temperature-resolved studies reveal compositional variations that correlate with the segregation of various elements during annealing. The complex O 1s, Sr 3d 5/2 and La 3d 5/2 spectra could be curve-fitted systematically with two La 3d 5/2 , three Sr 3d 5/2 and five O 1s contributions, respectively, using fixed binding energies and full widths at half-maximum. The trends are discussed and assignments are made on the basis of peak intensity and composition variations noted during the angle-and temperature-resolved studies, literature data and nearest-neighbor electronegativities. In all cases, elements present at the outermost surface revealed higher binding energies than their bulk-bound counterparts.

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X-ray photoelectron spectroscopy (XPS) along with inductively coupled plasma analysis (ICP-AE) and Raman spectroscopy have been used to define the location and to quantify the amount of iodine in HiPco SWNT samples loaded with molecular I(2) via sublimation (I(2)-SWNTs). The exterior-adsorbed I(2) can be removed (as I(-)) by reducing the sample of filled nanotubes with Na(0)/THF or by heating the I(2)-SWNTs to 300 degrees C (without reduction), leaving I(2) contained only within the interior of the SWNTs (I(2)@SWNTs) as proven by XPS. These I(2)@SWNTs contain approximately 25 wt % of I(2) and are stable without the loss of I(2) even after exposure to additional reduction with Na(0)/THF or upon heating to ca. 500 degrees C.