B and Y co-doped TiO2 photocatalyst with enhanced photodegradation efficiency

B and Y doped titanium dioxides (TiO 2 ) photocatalysts were synthesized by a sol-gel method followed by calcination . It is observed that the photodegradation efficiency of B and Y co-doped TiO 2 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 TiO 2 lattice Y 3+ ions tend to replace Ti 4+ ions while B 3+ ions occupy the interstitial sites. The incorporation of interstitial boron dopants will create oxygen vacancies ( Ov ·· ) and reduce Ti 4+ to Ti 3+ to form [ Ov ·· -Ti 3+ ] + complex, which traps the carriers and prolongs carrier lifetime. Moreover, Y 3+ ions can trap the photo-excited electrons to form Y 2+ ions, which will then react with the absorbed O 2 on TiO 2 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.