الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The amount of freshwater needed for human consumption has declined in recent years
due to many factors such as population growth, economic development, and changing
consumption patterns. A great challenge for this century lies in cleaning up the waste
generated during industrial, domestic, and agricultural activities. As a vital part of the life
cycle, water is heavily affected by these activities and eventually, becomes not suitable for
use. Among the numerous contaminants found in water, heavy metals and organic
contamination require special attention, as they are non-biodegradable and, even at low
concentration, have short and long-term adverse effects. Numerous techniques were
proposed to overcome this problem. Photocatalytic and adsorption degradation techniques
are effective, economical, friendly, and energy-saving strategies for eliminating organic
and inorganic contaminants from the water resources. Great attention was given to the core-
shell and 2D nanomaterials for water remediation because of their extraordinary properties
and promising applications. The core-shell nanoparticles, include Agcore- Aushell and Aucore-
Agshell core-shell nanoparticles, while 2D nanomaterials include boron nitride nanosheets
(BNNss) and graphene oxide (GO) nanosheets, which are very promising materials. These
nanomaterials investigated in various ways for advanced applications. Moreover, due to
the several factors influencing 2D material electronic structure, many studies have been
reported about the photocatalytic and adsorptive properties of these nanomaterials.
This thesis is based on synthesizing and processing of different nanomaterials, including
bimetallic core-shell nanoparticles, GO nanosheets, and BNNss for their applications in the
removal of pollutants from water. Bimetallic core- shell nanoparticles were prepared using
laser ablation in liquid. At first, gold and silver nanoparticles were prepared by ablating
gold and silver targets immersed individually in distilled water via a focused Nd:YAG laser
beam. Then, different metal targets have been ablated in a primary colloidal solution. The
laser ablation process was optimized to generate core-shell particles with controlled
properties.
GO nanosheets were prepared using the modified Hummers method. Hexagonal boron
nitride was processed using the mechanical exfoliation method to produce BNNss. To
accurately identify the optical properties and structures of each nanomaterial, different
III
techniques including ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron
microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction
(XRD), Raman spectroscopy, N2 adsorption-desorption analysis, and Zetasizer analysis
(ZS) were utilized.
Metal and bimetal nanoparticles have been used for photocatalytic studies, under visible
light irradiation and using methylene blue (MB) as a represented organic dye. A
comparative study was carried out on the photocatalytic degradation performance of silver
and Agcore Aushell. The degradation efficiency percentage of Ag NPs was 88.8% at 70 min
while Agcore Aushell within 70 minutes with degradation efficiency 95.4 %.There is an
enhancement in photocatalytic degradation performances of the Agcore Aushell than silver
nanoparticles.
The kinetic results of the adsorption mechanism for GO and BNNs show that the
pseudo-second-order model fitted the experimental data for Pb(II) and Cu(II). Furthermore,
several isotherm models were proposed to fit the adsorption of Pb(II) and Cu(II) over the
GO and BNNss. The Langmuir model represented the best fitting with the experimental
data with a maximum adsorption capacity of BNNss of 1711.3 and 1070.6mg/g for Pb(II)
and Cu(II), respectively. Moreover, the maximum adsorption capacity using the Langmuir
model for GO nanosheets was 1920.3 and 1600.2mg/g for Pb(II) and Cu(II), respectively.
The adsorption capacity obtained for GO and BNNss was higher than that of all earlier
studies reported.
Lake Qarun is located about 80km in the south west of Cairo, Egypt. Although Lake
Qarun was considered an environmentally protected area back in 1989, the lake has hardly
been protected from various polluting elements. It suffers from a significant pollution
problem due to uncontrolled solid and liquid domestic and industrial waste disposal
practices. The 2D nanosheets optimized in this thesis were used to treat Lake Qarun water
samples. The 2D nanomaterials adsorbed lead and copper in addition to many heavy metals
such as Fe, Cr, Cu, Pb, and Cd with high efficiency.
To sum up, this thesis offers various smart nanomaterials preparation for different uses
in environmental water treatment which can be investigated develop and applied on a large
scale in the future.