سال انتشار: ۱۳۸۷

محل انتشار: دومین کنگره بین المللی علوم و فناوری نانو

تعداد صفحات: ۲

نویسنده(ها):

F. F. Bamoharram – Department of Chemistry, Islamic Azad University-Mashhad Branch
M. M. Heravi – Department of Chemistry, Azzahra University
M Roshani – Department of Chemistry, Islamic Azad University-Mashhad Branch
L Jodeyre –

چکیده:

Catalysts are usually nanoparticles composed of clusters of atoms, often metals, with particle size varying between 1-20 nm. There are two types of nanocluster catalysts that carry out chemical reactions with high rates and selectivity [1]. Enzymes are nature’s catalysts, and many of them are composed of inorganic nanoclusters surrounded by high molecular weight proteins. Synthetic catalysts, either heterogeneous or homogeneous, are often metal nanoclusters that are used in the chemical technologies to carry out reactions with high turnover and selectiviy. The evolution of the field of catalysis is strongly coupled to the development of nanoscience and nanotechnology at the present. Heteropolyacids are a new branch in the field of nanocatalysts, and some attractive researching progresses have developed in recent years. They are well-defined early transition metal-oxygen clusters with unique structural characteristics and multiple functions [2]. Among a wide variety of studied heteropolyacids with different size and structures, the catalytic behavior of the Preyssler catalyst has been largely overlooked.The main objective of this work is to extend the catalytic behavior of the Preyssler as a nanocatalyst. In our earlier work we have synthesized and characterized the Preyssler nanocatalyst and studied the behavior of it as a nanocatalyst, slightly [3]. This research, in continuation of our earlier work [3] and our researches on catalytic behavior of heteropolyacids [4] has been done. Because of importance elimination of azo dyes, a large and systematic study has been done for photodegradation of azo dyes by ultraviolet spectroscopy in the presence of this nanocatalyst. The effect of various parameters such as pH, concentration of catalyst and oxidant on the rate of photodegradation were investigated and decolorization degree along with the first order constants were calculated