Photocatalytic enhancement of TiO2 by B and Zr co-doping and modulation of microstructure

Visible-light photodegradation test revealed that B and Zr co-doping can raise the photocatalytic ability of the undoped TiO 2 by a fold. XRD crystallography and Raman phonon spectroscopy measurements suggest that the Zr 4+ ions replace the Ti 4+ ions while the B 3+ ions occupy the interstitial sites, expanding the unit-cell volume and reducing crystallite size. The incorporation of interstitial boron dopants creates oxygen vacancies (Ov ) and reduce Ti 4+ to Ti 3+ to form [Ov -Ti 3+ ] + , which traps the carriers and prolongs carrier lifetime. Moreover, Zr 4+ ions replace Ti 4+ ions and form impurity levels, which could improve visible light response. The co-doped samples are benefited from both B interstitials and Zr substitutes.