Τίτλος:
Preparation of photoactive nitrogen-doped rutile
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
An easy way of preparing highly N-doped rutile photocatalysts (N-TiO 2 /R) in tubular furnace in a constant ammonia (NH 3 ) flow at 800-1000 °C temperature range is presented. New materials were compared to TiO 2 samples prepared at the same temperatures in air atmosphere as well as to the starting material. Complete transformation of amorphous and anatase phases to rutile was confirmed by XRD method. Successful incorporation of relatively high amounts of nitrogen (up to 17% at.), in form of either TiO 2 (N), TiO x N y or TiN, on photocatalysts' surface and in their lattice was confirmed using XPS and XRD analysis. Also presence of Ti 3+ was revealed by EPR studies. In contrast to pristine TiO 2 , the UV-vis/DR absorption spectra of N-modified photocatalysts extended significantly into the visible light region. Whereas nitrogen concentration as well as visible light absorption were found to increase with increasing modification temperature, photocatalytic activity was, on the contrary decreasing. This may be due to the very high nitrogen concentration, obtained at higher modification temperature, as well as the presence of small amount of conductive TiN phase on the N-TiO 2 /1000 °C photocatalyst surface. The artificial solar light activity of new photocatalysts after thermal treatment in NH 3 increased in comparison to starting material, due to nitrogen modification and presence of Ti 3+ ions. Activity under UV(-vis) light, though, decreased after modification procedure, probably due to smaller surface areas of new photocatalysts and complete anatase to rutile transformation. © 2012 Elsevier B.V. All rights reserved.
Συγγραφείς:
Dolat, D.
Moszyński, D.
Guskos, N.
Ohtani, B.
Morawski, A.W.
Περιοδικό:
Applied Surface Science
Λέξεις-κλειδιά:
Atmospheric temperature; Electron spin resonance spectroscopy; Heating furnaces; Light; Light absorption; Nitrogen; Oxide minerals; Paramagnetic resonance; Photocatalysis; Photocatalysts; Semiconductor doping; Semiconductor materials; Tin; Titanium nitride, Anatase-to-rutile transformations; Catalytic properties; Electronic paramagnetic resonance; Modification temperature; N-Doping; Nitrogen concentrations; Photocatalytic activities; Visible light absorption, Titanium dioxide
DOI:
10.1016/j.apsusc.2012.12.048
