2.
Silver nanoparticles are nanoparticles of silver,
i.e. silver particles of between 1 nm and 100 nm
in size.
There are many different synthetic routes to
silver nanoparticles. They can be divided into
three broad categories: physical vapour
deposition,ion implantation,or wet chemistry.
3. We report synthesis of silver nanoparticles by
reducing Tollens’ reagent with an aldehyde
such as formaldehyde in presence of sodium
citrate in aqueous medium. The resulting
nanoparticles were found to be stable upto a
few months and were characterized using UVVIS Spectroscopy,SEM, TEM,HRTEM and
SAED
4. Aims:-Synthesis of silver nanoparticles at room
temperature by tollen’s reagent.
Characterization of nanoparticles.
Applications in the fields of medicine and
catalysis.
Objectives:1)
To show room temperature feasibility of
formation of silver nanoparticles.
2)
To demonstrate increased reactivity of activated
silver ions from tollen’s reagent,towards weak
reducing agents.
5.
The nanoparticles were synthesized by the
bottom-up approach.
The synthesis is carried out by the chemical
reduction of Tollens' reagent. This method
allows selective synthesis of silver
nanoparticles.
6.
The reaction is carried out at the room
temperature in presence of trisodium citrate
as a capping agent.
The resulting yellow solution indicates the
formation of the silver nanoparticles ranging
from the sizes 5-50nm.
8.
The nanoparticles were characterized by the
analytical techniques such as UV-VIS
spectroscopy, SEM, TEM, HRTEM and SAED.
The results are in concurrence with the
existing literature
16.
Silver nanoparticles show antimicrobial activity
and they can kill any microorganism within 6
mins without harming the human tissues.
Therefore, they can be used in water
purification systems.
17.
Silver nanoparticles also used in the Surface
Enhanced Raman Spectroscopy(SERS).
Silver nanoparticles have been used as the
cathode in a silver-oxide battery.
They can also be used as a heterogeneous
catalysis due to the very high surface area.
They can also be used as a bone cement.
18.
As mentioned before silver nanoparticles can
be used in the catalysis of heterogeneous silver
catalysed reactions due to their high surface
area to volume ratio.The surface area increment
due to the use of nano-catalysts is about 2 *
10^6 times that over bulk catalysts.Hence these
nanoparticles can be used as catalysts in
reactions like silver catalysed
coupling,benzylation and alkylation reactions.
19.
Silver nanoparticles can be used in the formation
of nanocages of palladium i.e when reacted with
the solution of Na2PdCl4 palladium nanocages are
formed.Nanoporous nanoparticles of platinum can
be made in the same way i.e by using silver
nanoparticles.
An advantage of these nanoporous particles is that
they have a surface area increment of around 2 *
10^9 times that over bulk catalysts.These particles
of platinum can then be used as catalysts in
chemical processes(e.g:-contact process)
