Synthesis of reduced C,N-TiO₂ for catalytic oxidation of HCHO indoors

Abstract

Indoor HCHO pollution was becoming an issue with the increase of space confinement. In this article, C,N-TiO₂ was prepared by the sol–gel method at low temperature and a series of r-C,N-TiO₂ at different temperatures were synthesized under N₂. The materials were characterized by UV–Vis, FT-IR, PL, XRD, SEM, BET, and XPS. BET revealed the C,N-TiO₂ had larger specific surface area than P25; XPS and PL illustrated the existence of surface oxygen vacancies and defects. The concentration of HCHO was determined by the phenol spectrophotometric method. The larger specific surface area and plentiful surface hydroxyl groups can effectively capture HCHO and O₂ molecules; the surface oxygen vacancies and defects were conducive to generation of active oxygen species, which was benifit for the decomposition of HCHO. Among the prepared materials, r-C,N-TiO₂(400) has best catalytic oxidation activity for HCHO at room temperature and can reduce HCHO concentration to 0.06 mg/m³. This system was useful in gas purification with low production cost.

Graphical abstract

Keywords:

• HCHO
• phenol spectrophotometric method
• catalytic oxidation
• reduced C,N-TiO₂

Acknowledgements

We are thankful for the financial support by the Longitudinal Fund Project of Henan (130-53210131) and the Program for Talent introduction of Zhengzhou University (130-56309500).

Disclosure statement

No potential conflict of interest was reported by the authors.