Could you provide DOIs of papers on only interstitially nitrogen-doped TiO2? I need that the concentration of Ni was given there, as well as the absorbance spectrum.
is suitable! However, the authors gave a value of 19.22at.%N in their specimen, that, judging from their UV-VIS spectra, seems not correct. For example, in http://www.ncbi.nlm.nih.gov/pubmed/23511091 , the concentration of Ni in their TiO2 evaluated from the XPS measurements was just ca. 2 at.%. Look at the N-doped TiO2 curve. In comparison to undoped sample, it shows incredible result in the UV-VIS region! Actually, the absorbance in the region of 425-600 nm of the sample in http://www.sciencedirect.com/science/article/pii/S0926337314002987 is almost 37 times lower than the absorbance in the region of the specimen obtained in http://www.ncbi.nlm.nih.gov/pubmed/23511091