Improvement in Photocatalytic Activity of TiO2under Visible Irradiation through Addition of N-TiO2

This work is focused on improvement in photocatalytic activity of anatase-TiO2 (a-TiO2) photocatalyst under visible-light irradiation by adding nitrogen-doped TiO2 (N-TiO2) for depression of recombination rate between photoexcited electron and hole. The composites (a-TiO2/N-TiO2) were prepared by grinding in ethanol solvent at 200 rpm for 15 min with change in weight ratio of N-TiO2. In addition to the characterizations by X-ray diffraction and X-ray photoelectron spectroscopy, measurements of existing singlet oxygen by chemiluminescens method and photocatalytic activity by using NO(x) decomposition were conducted. The increases in singlet oxygen and photocatalytic activity have been observed and the phenomena are discussed based on the efficient prevention of recombination between photoexcited electron and hole within the prepared composite.