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conferenceseries
.com
RRJOMS | Volume 5 | Issue 4 | July, 2017
July 27-29, 2017 Vancouver, Canada
10
th
International Conference on
Emerging Materials and Nanotechnology
Res. Rev. J Mat. Sci. 2017
DOI: 10.4172/2321-6212-C1-003
Enhancement of catalytic activity of Au/TiO
2
by thermal and plasma treatment for CO oxidation and
preferential oxidation
Asif Mahmood
and
Waheed A Al Masry
King Saud University, KSA
A
significant enhancement in the catalytic activity of Au/TiO
2
in CO oxidation and preferential oxidation reaction by
creating the active sites on the catalyst surface by thermal treatment as well as by producing small gold particles by plasma
treatment has been studied. Au/TiO
2
catalyst (Au (1 wt.%) supported on TiO
2
) was prepared by conventional deposition-
precipitation method with NaOH (DP NaOH) followed by washing, drying and calcination in air at 400
o
C for 4h. Thermal
treatment of Au/TiO
2
was carried out at 450
o
C under 0.05 mTorr. A small amount of Au/TiO
2
catalyst was taken from the
untreated and thermally treated Au/TiO
2
and both kinds of catalysts were treated with plasma sputtering at room temperature.
The activity of the catalysts has been examined in the reaction of CO oxidation and preferential oxidation (PROX) at 25-250
o
C.
Thermally treated Au/TiO
2
showed better catalytic activity as compared to the untreated catalyst. There is also an additional
enhancement in the catalytic activity due to plasma sputtering on the both kinds of catalysts. Thermally treated Au/TiO
2
followed by plasma sputtering Au/TiO
2
showed higher conversion rates for CO oxidation reaction compared with untreated,
thermally treated and plasma sputtered Au/TiO
2
catalysts. It may be concluded that the enhancement of catalytic activity of
thermally treated Au/TiO
2
followed by plasma sputtering owing to the generation of active sites such as oxygen vacancies/
defects in TiO
2
support using thermal treatment as well as by producing small gold particles using plasma treatment.
ahayat@ksu.edu.saSynthesis and characterization of hematite nanoparticles for arsenite removal from aqueous medium
Herlys Viltres Cobas
1
, Oscar F Odio Chacon
2
, Susel Del Sol Fernandez
1
, Raul Borja Urby
3
and
Edilso Reguera Ruiz
1
1
Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Mexico
2
Instituto de Ciencia y Tecnología de Materiales, Cuba
3
Centro de Nanociencias y Micro y Nanotecnologías, Mexico
A
rsenic-contaminated groundwater, used as drinking water, has been creating several problems in different countries around
the World. The present existing reports of diverse countries showed arsenic concentrations in drinking water is much
higher than those proposed by the World Health Organization (10 µg/L). Nanomaterials and nanotechnologies inspire new
possible solutions to major environmental issues nowadays. It has been reported that adsorption strategies using nanoparticles
turned beneficial as hematite proved to be very efficient for the removal of arsenic in drinking water. However, the adsorption
mechanism is not yet clear. In order to shed light on this subject, we attempt to study the interactions between arsenic species
and α-Fe
2
O
3
nanoparticles in aqueous medium. The iron oxide nanoparticles were prepared using a solvothermal method.
Synthesized hematite nanoparticles were put in contact with As
2
O
3
solutions at room temperature and at pH 4 and 7. The
nanoparticles were characterized by FTIR, XRD, UV-vis, XRF and XPS. The results showed that synthesized nanoparticles
had an average diameter of crystallite of 30 nm and from XRD pattern also was confirmed a rhombohedra hexagonal close-
packed phase for the powders obtained (α-Fe
2
O
3
). From optical studies was evidenced that hematite nanoparticle obtained,
have semiconductor properties due to band gap value, in this case 2.2 eV. The presence of arsenic on particles surface was
confirmed, which is more remarkable when pH=7 condition is employed. On the other hand, after adsorption experiment,
it was evident from FTIR and XPS that once arsenic species interact with the nanoparticles, they form mono and bi-dentate
surface complexes. The developed methodology could be implemented in the water treatment industries, reducing the costs of
the processes and making them more environmental friendly.
herlysvc.231289@gmail.com