کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
56486 47084 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photocatalytic properties of aqueous systems containing TiO2 nanoparticles
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Photocatalytic properties of aqueous systems containing TiO2 nanoparticles
چکیده انگلیسی

This work describes the aging of aqueous colloidal TiO2 nanoparticles at different temperatures and pH values. Emphasis was particularly given to the behaviour in the alkaline region, since this has not yet been properly reported. Aging of colloidal TiO2 suspensions has previously been investigated using spectroscopic methods (band gap energy determination) and a dynamic light scattering method (particle size determination). The photocatalytic activity, representing the most important property of TiO2 nanoparticles, was determined through the quantum yield of 4-chlorophenol degradation. It was found that the size of acidic colloidal TiO2 particles depends on the storing temperature; lower temperature leads to a small increase in particle size. The process of aging of TiO2 nanoparticles consists in slow re-crystallization that leads to slightly larger particles, and it seems that this process is faster at higher temperatures. In alkaline environments it was found that the change in particle size depends on the type of alkaline reagent used (KOH and NH4OH), on its concentration and also on the starting concentration of the TiO2 suspension. In contrast to the quantum yield of acidic TiO2, the quantum yield of alkaline suspensions decreased during aging.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Catalysis Today - Volume 161, Issue 1, 17 March 2011, Pages 140–146
نویسندگان
, , , , , ,