Enhanced visible photocatalytic activity of nitrogen doped single-crystal-like TiO_2 by synergistic treatment with urea and mixed nitrates

摘要

N-doped single-crystal-like TiO_2 is claimed to be a very promising material among various catalytic. In this paper, N-doped single-crystal-like TiO_2 (N-S-TiO_2) samples were firstly prepared by molten salt method with urea and mixed nitrates as synergistic doping agents, therein, the mixed nitrates works also as a morphology modifier to form a single-crystal-like structure in the sample. The nitrogen content in the N-S-TiO_2 sample could be improved because of the adding of NaNO_3 and KNO_3 mixed nitrates compared with using urea as a single nitrogen source. UV-Vis absorption spectroscopy analysis indicated that the nitrogen doped TiO_2 has a red shift of the light absorption edge. The presence of N-O bonds on the surface of the N-S-TiO_2 samples could be confirmed by x-ray photoelectron spectroscopy. The degradation efficiency of N-S-TiO_2 to methylene blue under visible light is the best compared with different TiO_2 samples without the treatment of mixed nitrates.