Hybridizing TiO₂ with nitrogen-doped carbon: A new route to a highly visible light-active photocatalyst

TiO₂ hybridized with nitrogen-doped carbon (N-doped C/TiO₂) was prepared as a photocatalyst with improved visible-light catalytic activity for the first time. It was found that N-doped carbon was formed by etching and partial decomposition of as-formed graphitic carbon nitride on the surface of TiO₂ under calcination at 500 °C in open air, which avoided direct doping of nitrogen into TiO₂ structure. N-doped carbon on the surface of TiO₂ led to an enhanced light absorption in the range of 400 to 550 nm. The resulting N-doped C/TiO₂ exhibited about 2 times higher activity than the graphitic carbon nitride/TiO₂ prepared by direct carbonization in argon atmosphere. Compared with the commercial TiO₂ (Degussa, P25), N-doped C/TiO₂ showed a higher reaction rate in the degradation of various pollutants such as rhodamine B, phenol and methyl orange (MO) under simulated solar light irradiation.