A passivated codoping approach to tailor the band edges of TiO2 for efficient photocatalytic degradation of organic pollutants

We propose an effective passivated codoping approach to tailor the band edges of TiO2 by doping the host with group IVA and group VIB impurities to passive donor-acceptor complexes. A way of achieving p-type TiO2 is found, which can outspread the application range of TiO2 semiconductor. It is demonstrated that the carbon (C)/tungsten (W) codoped TiO2 has a substantial increase in the valence band edge, while leaving the conduction band edge almost unchanged, thus improving the efficiency of photocatalytic degradation of organic pollutants. In principle, the suggested approach for overcoming the p-type doping bottleneck can be applied to other wide-band-gap semiconductors. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3174917]