N-TiO₂-coated polyester filters for visible light - Photocatalytic removal of gaseous toluene under static and dynamic flow conditions

The present work aims to utilize N-TiO₂ coating for decontamination of gaseous pollutants under normal room light irradiation. N-TiO₂ nanoparticles were prepared by incomplete thermal oxidation of TiN at different temperatures to achieve self-doping of TiO₂ to improve simultaneously the structural, morphological, and electronic properties of conventional TiO₂ photocatalyst. The thermal evolution of TiN to oxygen-rich titanium oxynitride (N-TiO₂) and subsequently TiO₂ at different temperatures is characterized systematically by different tools including XRD, TEM, XPS, UV-vis diffuse reflectance and SPV responses. The synthesized N-TiO₂ was coated onto polyester filters using a facile spray coating method. The excellent photocatalytic performance was successfully demonstrated on mineralization of gaseous toluene with fluorescent light irradiation under both static and dynamic flow conditions in a comprehensive custom-built photocatalytic test system. Therefore, it shows promising potential to be utilized in practical air purification applications.