In this study, nitrogen was used as a dopant to defect into the TiO2 lattice making contributions to the visible light absorption of nitrogen-doped TiO2. N-TiO2 material was prepared from K2TiF6 and NH3 as precursors. The N-TiO2 photocatalyst was prepared under the condition of 1 M NH3 solution, 14 % N/TiO2 mass ratio and the calcination temperature of TiO(OH)2 was 600 oC for 5 hours. The obtained results indicated that the simultaneous existence of both anatase and rutile phase of pattern of N-TiO2 and the average particle size was approximately 30 nm. Modification of titania with nitrogen significantly changed the light absorption ability of the catalyst. The UV-vis spectrum of N-TiO2 showed the absorption maximum at 400 nm with band gap eV. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 20, SOÁ T4- 2017 Preparation of N-TiO2 nanomaterial and evaluation of its photocatalytic activity under visible light • Nguyen Thi Dieu Cam Quy Nhon University • Mai Hung Thanh Tung Ho Chi Minh City University of Food Industry (Received on 10th November 2016, accepted on 30th October 2017) ABSTRACT In this study, nitrogen was used as a dopant to defect into the TiO2 lattice making contributions to the visible light absorption of nitrogen-doped TiO2. N-TiO2 material was prepared from K2TiF6 and NH3 as precursors. The N-TiO2 photocatalyst was prepared under the condition of 1 M NH3 solution, 14 % N/TiO2 mass ratio and the calcination temperature of TiO(OH)2 was 600 oC for 5 hours. The obtained results indicated that the simultaneous existence of both anatase and rutile phase of pattern of N-TiO2 and the average particle size was approximately 30 nm. Modification of titania with nitrogen significantly changed the light absorption ability of the catalyst. The UV-vis spectrum of N-TiO2 showed the absorption maximum at 400 nm with band gap eV. The results of photocatalytic experiment proved that, the N-TiO2 exhibited the photocatalytic activity for degradation of methylene blue even under visible light better than that of TiO2. Key words: Titanium dioxide, nitrogen-doped, photocatalyst, methylene blue, visible light INTRODUCTION TiO2 is a popular photocatalyst for degradation of toxic organics owing to the advantages of earth abundance, low toxicity, and chemical stability. It has been well documented that an electron-hole pair is generated when a TiO2 photocatalyst is excited by UV irradiation, which requires energy that is equal to or higher than its band gap energy. The electron-hole pairs react with water, hydroxyl groups, and molecular oxygen absorbed on the TiO2 surface, generating reactive oxygen species such as the hydroxyl radical (•OH) and superoxide anion ( •O2−). These radical species participate in oxidation .
