الفهرس 
CHAPTER I: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
A clean and high-throughput synthesis of Gold@chitosan
(Au@Cs) nanocomposite using nontoxic oxalic acid as a reducing agent
was developed. The synthetic route was carried out in completely dry
conditions, i.e. solid-state reaction. The gold nanoparticles were bound
with Cs through the hydroxyl and amino groups, as confirmed by Fourier
transform infrared spectroscopic analysis. Scanning and transmission
electron microscopy imaging confirmed the formation of semi-spherical
gold particles. The catalytic performance of the synthesized Au
nanoparticles for the reduction of chromium (VI) in the presence of
formic acid was evaluated. The film-forming ability of Cs enabled the
design of separable/reusable heterogeneous catalyst which is convenient
for real industrial applications. The proposed solid-state synthetic route
could be adapted to produce a wide variety of nanostructured materials
that are characterized by high-yield, greenness, and low cost in very
simple steps.
Silver@chitosan (Ag@Cs) nanocomposite was prepared by the
same strategy without a need for reducing and/or stabilizing agents. The
shape, size, and crystalline phase were studied using UV-visible
spectroscopy, transmission electron microscopy, scanning electron
microscopy and X-ray diffraction. The nature of the interaction between
the Cs and Ag nanoparticles was studied using the Fourier transformer
infrared spectroscopy. The as-prepared Ag@Cs nanocomposite showed
high activity in the catalytic reduction of 4-nitrophenol (4-NP) to 4-
aminophenol (4-AP) in the presence of an excess amount of NaBH4.
Furthermore, the Ag@Cs film is easily separable, as well as remains
active after reused for 10 times. The Ag@Cs nanocomposite film could
be a promising candidate for various catalytic reactions.