Carbon-Doped TiO2 and Carbon, Tungsten-Codoped TiO2 through Sol-Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis
|Title:||Carbon-Doped TiO2 and Carbon, Tungsten-Codoped TiO2 through Sol-Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis||Authors:||Neville, Elaine M.
Mattle, Michael J.
MacElroy, J. M. Don
Sullivan, James A.
|Permanent link:||http://hdl.handle.net/10197/3981||Date:||9-Aug-2012||Abstract:||A series of C-doped, W-doped, and C,Wcodoped TiO2 samples have been prepared using modified sol-gel techniques. Reproducible inexpensive C-doping arises from the presence of melamine borate in a sol-gel mixture, whereas W-doping is from the addition of tungstic acid to the sol. The materials have been characterized using elemental analysis, N2 physisorption (BET), thermogravimetric analysis, X-ray diffraction, Raman, X-ray photoelectron, UV-vis spectroscopies, and photocatalytic activity measurements. Doping C and W independently results in an increased absorbance in the visible region of the spectrum with a synergistic effect in increased absorbance when both elements are codoped. The increased visible-light absorbance of the W-doped or codoped materials is not reflected in photocatalytic activity. Visiblelight- induced photocatalytic activity of C-doped material was superior to that of an undoped catalyst, paving the way for its application under only visible-light irradiation conditions. A significant fraction of the spectral red shift commonly observed with doped catalysts might be due to the formation of color centers as a result of defects associated with oxygen vacancies, and bandgap-related narrowing or intragap localization of dopant levels are not the only factors responsible for enhanced visible-light absorption in doped photocatalysts. Furthermore, bandgap narrowing through increases in the energy of the valence band may actually decrease photo-oxidation activity through a curtailment of one route of oxidation.||Type of material:||Journal Article||Publisher:||American Chemical Society||Copyright (published version):||2012 American Chemical Society||Keywords:||TiO2;Photocatalysis;Band gap engineering;Solar energy||DOI:||10.1021/jp303645p||Language:||en||Status of Item:||Not peer reviewed|
|Appears in Collections:||Chemistry Research Collection|
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