Abstract
The surface structures of doped semiconductor photocatalysts play a vital role in determining visible light absorbance, transfer and redox potentials of charge carriers, as well as the inhibition of recombination. We examine the photocatalysis of anatase TiO2 with surface terminating Ti-O-B-N structures from both experimental and computational perspectives. This codoped titania system shows much better photocatalytic activity in generating center dot OH radical species and degrading organic pollutants in comparison with B-doped anatase titania. We present indicative evidence that the Ti-O-B-N surface structures can exhibit bifunctionality in promoting photocatalysis, (i) supplying partially occupied localized states attributed to B-N coupling with spectral distribution that is advantageous for enhancing visible light absorption and (ii) acting as photocatalytic "hot sites" to support localization and separation of charge carriers at the surface. These results offer important implications for designing highly efficient photocatalysts based on codoping strategies.