| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 148685 | Chemical Engineering Journal | 2013 | 7 Pages |
•(Fe,N) co-modified rutile was prepared via impregnation–calcination method.•Fe-single modified and N-single modified rutile was prepared for comparison.•All modified materials exhibit higher visible light activity than commercial rutile.•Excellent synergistic effect of co-modification confirmed by action spectra studies.•Very high activity of co-modified rutile up to 560 nm wavelength was revealed.
A simple method of preparation of visible-light active rutile-TiO2 photocatalysts is presented. New materials were obtained by modification of a commercial amorphous titanium dioxide via impregnation followed by calcination at 800 °C processes. Series of Fe-modified TiO2 with different Fe:TiO2 ratios (1, 5 and 10 wt.% of Fe) were obtained by impregnation with Fe(NO3)3 followed by calcination in argon atmosphere. Nitrogen-modified TiO2 was prepared by calcination of the commercial titania in ammonia atmosphere at 800 °C. Finally (Fe,N) co-modified samples were prepared by combining impregnation with calcination in ammonia atmosphere. The materials were characterized by the following methods: X-ray power diffraction (XRD), X-ray photoelectron spectroscopy (XPS), elemental analysis, UV-Vis/DR spectroscopy, scanning electron microscopy (SEM) and N2 adsorption at 77 K. The photocatalytic activity of the new materials was studied during oxidative decomposition of acetic acid under visible light irradiation using mercury lamp and a cut-off filter providing wavelength longer than 400 nm. Additionally, the so-called action spectra measurements of photocatalytic activity as a function of irradiation wavelength were conducted. The results revealed an excellent increase in the visible light photoactivity of the co-modified samples in comparison with the single-modified ones, which was ascribed to the synergistic effect of the N,Fe rutile co-modification. Nitrogen caused a band-gap narrowing allowing absorption of longer wavelengths from visible light region, whereas iron increased the efficiency of charge separation. As a result, a significantly improved photocatalytic performance of the materials was observed.
