Indexed on: 02 Nov '16Published on: 01 Nov '16Published in: Journal of Alloys and Compounds
B and Y doped titanium dioxides (TiO2) photocatalysts were synthesized by a sol-gel method followed by calcination. It is observed that the photodegradation efficiency of B and Y co-doped TiO2 is twice that of undoped sample. To explore the underlining mechanism, x-ray diffraction, Raman, scanning electron microscope, x-ray photoemission, and UV–Vis diffuse reflectance spectroscopy measurements have been carried out to investigate the effect of B and Y doping on the structural, electronic, and optical properties of titania. Experimental observations revealed that in TiO2 lattice Y3+ ions tend to replace Ti4+ ions while B3+ ions occupy the interstitial sites. The incorporation of interstitial boron dopants will create oxygen vacancies (Ov··Ov··) and reduce Ti4+ to Ti3+ to form [Ov··Ov··-Ti3+]+ complex, which traps the carriers and prolongs carrier lifetime. Moreover, Y3+ ions can trap the photo-excited electrons to form Y2+ ions, which will then react with the absorbed O2 on TiO2 surface to generate reactive species. In addition, all the doped samples have smaller crystallite sizes. The formation of B interstitials and Y substitutes, and increased surface-to-volume ratio are all beneficial to improve photocatalytic activity.