کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
28337 44071 2007 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Comparison of photooxidation and photoreduction reactions on TiO2 nanoparticles
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Comparison of photooxidation and photoreduction reactions on TiO2 nanoparticles
چکیده انگلیسی

Photooxidation and photoreduction reaction rates on nanoparticulate TiO2 have been studied using a series of silica coated samples prepared from the same parent material—a high area rutile. Oxidation of propan-2-ol was measured by GC analysis of acetone product. Reduction of DPPH (1,1-diphenyl-2-picrylhydrazyl radical) was followed by the decrease in absorbance at 520 nm and photogreying of TiO2 was measured as a change in L, the reflectance of the CIE Y illuminant centred at 550 nm, using a Minolta chroma meter.The activity for oxidation of propan-2-ol correlated well with two measures of photoreduction, the reduction of the stable DPPH and TiO2 photogreying in an oxygen free system.In all cases, low silica loadings resulted in a small increase in activity. For silica levels >1 wt.% the dependence of activity decreased with increasing levels of silica treatment. The pattern of activity versus silica-level was consistent with elimination of both photooxidation and photoreduction at 12–16% silica. A speculative interpretation of these changes was based on changes in the silica environment as determined by magic angle spinning NMR.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 186, Issues 2–3, 25 February 2007, Pages 115–120
نویسندگان
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