Synthesis, structural characterization, and photocatalytic properties of iron-doped TiO2 aerogels

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作者：

M Popa，L Diamandescu，F Vasiliu，CM Teodorescu，V Cosoveanu，M Baia，M Feder，L Baia，V Danciu

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摘要：

Fe(III)-doped TiO 2 aerogels are prepared by acid catalyzed sol–gel method followed by supercritical drying, and then heat treatment. Raman spectra together with X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns of the iron-doped TiO 2 aerogel samples revealed the existence of both anatase and brookite crystalline phases. It was found that the brookite phase formation is favored by the increase of the iron content in the dried samples. XRD measurements show that the lattice constant c of anatase phase decreases with the dopant addition, while the value of a remains essentially unchanged. The microstructure of the investigated samples is relatively compact with small mesopores as revealed from transmission electron microscopy (TEM). The most enhanced photocatalytic activity was exhibited by the TiO 2 aerogel sample with 1.8 at.% Fe(III) whose apparent rate constant of the salicylic acid photodegradation was found to be of almost six times higher than that of Degussa P25.

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关键词：

Experimental/ aerogels catalysis crystal microstructure drying electron diffraction heat treatment iron lattice constants photochemistry Raman spectra sol-gel processing titanium compounds transmission electron microscopy X-ray diffraction/ structural properties photocatalytic properties iron-doped aerogels acid catalyzed sol-gel method supercritical drying heat treatment Raman spectra X-ray diffraction XRD selected area electron diffraction anatase crystalline phase brookite crystalline phase lattice constant dopant addition microstructure transmission electron microscopy TEM salicylic acid photodegradation TiO 2:Fe / A8120 Other methods of preparation of materials A8140G Other heat and thermomechanical treatments A7830G Infrared and Raman spectra in inorganic crystals A6160 Crystal structure of specific inorganic compounds A6480G Microstructure A8270G Gels and sols A8250 Photochemistry and radiation chemistry A8265J Heterogeneous catalysis at surfaces and other surface reactio