Size controlled synthesis of highly dispersed anatase/rutile nanoparticles with photocatalytic activity toward salicylic acid degradation

作者：de Souza e Silva Juliana Martins; Pastorello Murilo; Strauss Mathias; Maroneze Camila Marchetti; Sigoli Fernando Aparecido; Gushikem Yoshitaka; Mazali Italo Odone

来源：RSC Advances, 2012, 2(12): 5390-5397.

DOI：10.1039/c2ra20453c

TiO2 nanocrystals supported in SBA-15 pores were prepared by a simple route of successive cycles of impregnation of SBA-15 with titanium(IV) di-(n-propoxy)-di-(2-ethylhexanoate) followed by thermal treatment. Anatase and rutile phases were identified by XRD in the materials obtained after cycles 1, 3, 5, 7 and 10. Raman scattering combined with XRD and TEM shows that titania is in a nanometric regime. Increases in the size of the titania nanocrystals, as well as increases in the TiO2 content in the final material (XRF), occur after successive cycles. SAXS and N-2 sorption indicate that the nanocrystals are formed inside the SBA-15 mesopores, which remain unblocked even after 10 cycles. UV-Vis (DRS) spectroscopy indicates important changes in electronic properties. The ability of SBA-15- supported titania nanocrystals to photodegrade salicylic acid was tested. There is a clear relation between the TiO2 nanoparticle size and the photocatalytic activity. Among all samples tested, the best result was obtained for the materials with the highest band-gaps and with the smallest sized titania.

• 出版日期2012