The ILs-assisted solvothermal synthesis of TiO2 spheres : the effect of ionic liquids on morphology and photoactivity of TiO2
Marta Paszkiewicz , Justyna Łuczak , Wojciech Lisowski , Paulina Patyk , Adriana Zaleska-Medynska
AbstractEffect of the ionic liquid (IL) structure (chain length in the imidazolium cation) on morphology and photoactivity of TiO2 particles has been systematically investigated. The TiO2 microspheres have been successfully synthesized via facile solvothermal method assisted by ionic liquids, such as 1-butyl-3-methylimidazolium chloride [BMIM][Cl] and 1-decyl-3-methylimidazolium chloride [DMIM][Cl] using tetra-tert-butyl orthotitanate (TBOT) as a TiO2 precursor. Surface properties were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction analysis (XRD), BET surface area measurement, elemental analysis (NCHS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was investigated by means of phenol photodegradation in the aqueous phase as a model pollutant, as well as formation of hydroxyl radicals based on detection of fluorescent product of coumarine hydroxylation. Surface properties of TiO2 particles were correlated with the type and amount of the IL used during preparation as well as with the photoactivity. Both mechanism of the TiO2 spheres formation in the presence of [BMIM][Cl] and [DMIM][Cl] likewise the mechanism of their photoexcitation were also discussed. It was found that both electrostatic stabilization as well as coordination by imidazolium cation was responsible for securing the growth of the TiO2 spheres. The XPS data clearly revealed that the amount of carbon in the form of NCN species (imidazole-metal bound formed through C-2 carbon in imidazole ring) corresponds well with the change of the photoactivity. The most active samples (phenol degradation rate: 5.9 mmol·dm−3·min−1) contained the highest amount of carbon in the form of NCN species (6.06 at.%) among all ILs-TiO2 samples.
|Journal series||Applied Catalysis B: Environmental, ISSN 0926-3373|
|Publication size in sheets||0.7|
|Keywords in English||ionic liquids, ILs-assisted synthesis, TiO2 microspheres, TiO2 particles, heterogeneous photocatalysis, solvothermal synthesis|
|Score|| = 45.0, 20-12-2017, ArticleFromJournal|
= 45.0, 20-12-2017, ArticleFromJournal
|Publication indicators||: 2016 = 9.446 (2) - 2016=8.87 (5)|
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