Characterization results show that N-doped TiO2 samples have a broader absorption spectrum and a higher antibacterial efficiency against E. coli than pure samples. The DFT calculation suggests that nitrogen ion doping induces the formation of new states closed to the valence band leading to a narrowing of the band gap and a great improvement in photocatalytic activity in the visible light region of the doped material. | JOURNAL OF SCIENCE OF HNUE Mathematical and Physical Sci. 2013 Vol. 58 No. 7 pp. 86-93 This paper is available online at http PHOTOCATALYTIC ANTIBACTERIAL PERFORMANCE OF N-DOPED TiO2 AGAINST ESCHERICHIA COLI Do Minh Thanh Nguyen Thi Khanh Hoa Nguyen Cao Khang and Nguyen Van Minh Center for Nano Science and Technology Hanoi National University of Education Abstract. Nitrogen-doped titanium dioxide TiO2 x Nx material has been prepared using the hydrolysis method. The effect of nitrogen on the structural and optical properties of the catalyst was investigated. The antibacterial ability of synthesized N-doped TiO2 samples was evaluated using inactivated Escherichia coli E. coli as a model for Gram-negative bacteria under visible irradiation. Characterization results show that N-doped TiO2 samples have a broader absorption spectrum and a higher antibacterial efficiency against E. coli than pure samples. The DFT calculation suggests that nitrogen ion doping induces the formation of new states closed to the valence band leading to a narrowing of the band gap and a great improvement in photocatalytic activity in the visible light region of the doped material. Keywords N-doped TiO2 E. coli photocatalyst. 1. Introduction TiO2 is the best well-known photocatalyst among the metal oxides due to its excellent physical and chemical properties 1 . Titania in the anatase phase has been widely applied in environmental treatments 2-5 . Furthermore TiO2 can be used as an antibacterial agent because of its strong oxidation activity and super hydrophilicity under appropriate irradiation. The photocatalytic biocidal effect of TiO2 was first reported by Matsunaga et al. in 1985 6 . They observed that microbial cells can be killed when a homogeneous solution of TiO2 -Pt catalyst and microbial cells was exposed to near-UV light. Afterwards numerous studies related to the bactericidal effect of TiO2 have been Received September 10 2013. Accepted October 28 2013. Contact .
