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Journal of Materials Science and Nanotechnology | Volume: 2
August 20-21, 2018 | Paris, France
Materials Science and Materials Chemistry
International Conference on
Mechanochemical synthesis of double perovskites materials mediated by ammonium
fluoride along with their optical and catalytic role in environmental remediation
Pooja Rawat
and
Rajamani Nagarajan
University of Delhi, India
B
ond breaking and bond making triggered by stress are
usually referred to as mechanochemical reactions. To
highlight the power of mechanochemistry to oxidize metal
ions leading to the discovery of newer phases, ammonium
fluoride mediated synthesis of A
2
MF
6
(A =Rb, K; M = Pd, Mn,
Ni) has been carried out. Stability of high oxidation state of
transition elements using mechanochemical approach has
been demonstrated. Grinding reactions of ammonium fluoride
with metal (II) acetate and further cation exchange with AF
(A = Rb, K) were closely monitored ex-situ characterizations
such as high-resolution PXRD, FT-IR and Raman spectroscopy
measurements. For the reaction involving AF (A= Rb, K),
A
2
MF
6
possessing K
2
PtCl
6
type structure was confirmed by
the Rietveld refinement of PXRD pattern, HR-TEM and SAED
measurements. Elemental composition and oxidation state
of palladium in Rb
2
6
were examined using XPS analysis.
Ligand to metal charge transfer and d-d transitions of Pd (IV)
were present in the UV-visible diffuse reflectance spectrum
of Rb
2
6
with a band gap of 2.67 eV estimated using the
Kubelka–Munk function. Other than LMCT, they also show a
broadband in the visible region for d-d transitions. Its role as a
photocatalyst to degrade the aqueous dye solutions (MB, RhB,
Rh6G and MG) under UV-visible radiation has been evaluated
along with their kinetic studies. The reduction of Pd (IV) to
Pd (0) by NaBH
4
has been favourably used for the efficient
and rapid conversion of highly carcinogenic, toxic, mutagenic
Cr
6+
to less toxic Cr
3+
. Application of Mn
4+
in K
2
MnF
6
as red
phosphors has been demonstrated by using PL spectroscopy.
e:
poojarawatchemistry@gmail.com