Effects of carbon doping on TiO₂ for enhanced visible light-driven NO sensing performance

Carbon doped TiO₂ (C-TiO₂) was successfully synthesized via a novel method using polyvinyl alcohol (PVA) to enhance visible-light photocatalytic activity. In addition, the effect of C doping of TiO₂ on the sensitivity of NO gas detection with visible light was studied. The investigation of the NO gas sensing performance shows C-TiO₂ enhanced the visible-light driven photocatalytic activity. It is shown that the visible-light driven photocatalytic activity of C-TiO₂ originated from the decrease in the band gap energy by C doping. The band gap energy of C-TiO₂ was 2.82 eV, which corresponds to the energy of photons with 440 nm light. It is thus demonstrated that the use of PVA provides a straightforward approach to synthesize C-TiO₂ for NO gas detection using visible light.