Doping mode, band structure and photocatalytic mechanism of B–N-codoped TiO 2

Abstract

The photocatalyst B and N codoped TiO 2 (B–N-TiO 2) was prepared via the sol–gel method by using boric acid and ammonia as B and N precursors. The doping mode, band structure and photocatalytic mechanism of B–N-TiO 2 were investigated well and elucidated in detail. B–N-TiO 2 showed the narrowed band gap and thus extended the optical absorption due to interstitial N and [NOB] species in the TiO 2 crystal lattice. The coexistence of interstitial N and [NOB] species in the TiO 2 crystal lattice and surface NO x species allowed the more efficient utilization of visible light. Simultaneously, interstitial [NOB] and N species and surface B 2O 3 and NO x species facilitated the separation of photo generated electrons and holes and suppress their recombination effectively. Hence, B–N-TiO 2 showed a higher photocatalytic activity than pure TiO 2, N-doped TiO 2 (N-TiO 2) and B-doped TiO 2 (B-TiO 2) under both UV and visible light irradiation.