الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
The field of nanoscience and nanotechnology has reached an interesting period of development and excitement in many scientific fields in the last few years. Many of the properties and phenomena associated with nanomaterials require the understanding of their chemistry because many of their applications are related to chemistry.
A scientific and technical revolution has just begun based
upon the ability to systematically organize and manipulate
matter at nanoscale. The field of nanostructure science and
nanotechnology is a broad and interdisciplinary area of
worldwide research and development activity that has been
growing explosively in the past few years. The products that
are created through nanostructuring have great potential and
significant commercial impacts at present. Nanotechnology is
defined as fabrication of devices with atomic or molecular
scale precision. Devices with minimum feature size are
considered to be products of nanotechnology [5].
When matter is as small as 1 to 100 nanometers, many of
its features will easily change and have many unique features
both different from macro-matters and single atoms due to the
quanta effect, regional confinement of matter, and huge surface
or interface effects. The final objective of nanometer
Chapter (1) Introduction
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technology is to produce products of special functions with
new physical and chemical features by making atoms,
molecules and matters presenting their features directly in the
length of a nanometer [5].
New materials are being discovered or produced and
astonishing claims are being made concerning their properties,
behaviors and applications. Research in this area is motivated
by the possibility of designing nanostructured materials that
possess novel electronic, optical, magnetic, photochemical and
catalytic properties such materials are essential for
technological advances in photonics, biotechnology, quantum
electronics, nonlinear optics, energy storage and information
storage and processing. Nanoscience and nanotechnology is an
important interdisciplinary area, which emerged in recent years
due to the unusual size and shape dependent physiochemical
and electronic properties of metallic and semiconducting
nanoparticles. These nanoparticles can be exploited in a wide
variety of technological applications like light emitting diodes,
sensors, solar cells, etc. Nanotechnologies cover a wide range
of fields (from Chemistry, Physics and Biology, to Medicine,
Engineering and Electronics). The factors which cause the
properties of nanomaterials to differ significantly from other
materials are increased relative surface area and quantumThe field of nanoscience and nanotechnology has reached an interesting period of development and excitement in many scientific fields in the last few years. Many of the properties and phenomena associated with nanomaterials require the understanding of their chemistry because many of their applications are related to chemistryThe environmental applications of photocatalysis using TiO2 nanoparticles have attracted a great deal of research efforts over the last three decades. It is well established that nanoparticles of TiO2 illuminated with UV light can degrade almost any dissolved organic pollutant to the degree of mineralization. Nevertheless, photocatalysis, particularly in the aqueous media, has still not been applied commercially for environmental purposes. One reason seems to be the cost associated with the requirement of using an expensive UV radiation source.The work presented in this thesis is divided into three chapters, references, and two summaries one of them is english and the other is arabic.This chapter includes a brief idea about nanotechnology, methods of synthesis of nanotechnology, application of nanotechnology, photocatalysis, mechanisms of photocatalysis, properties and applications of titanium dioxide. It also presents a brief idea about the synthetic methods of titanium dioxide nanoparticles and a brief idea about its modificationThis chapter includes the experimental conditions and the materials used to synthesis the undoped TiO2 nanoparticles by two different methods (the Sol-gel and the hydrolysis methods). In addition, this chapter includes the methods used to characterize TiO2 nanoparticles such as: Thermal Analysis (The thermogravimetric (TG), differential thermogravimetric (DTG)) and the differential scanning calorimetry (DSC), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and UV-visible SpectroscopyThe XRD results also showed that the oxides obtained by the hydrolysis method, in the basic medium (ammonium hydroxide), contain only anatase phase, while calcination at the same temperature of the sample synthesized in the acidic medium (nitric acid) resulted in the formation of two phases (anatase and rutile).
- The FT-IR results showed the presence of surface hydroxyl groups and water molecules adsorbed at the surface of the calcined oxides at 480 °C.The band gap has been calculated from the UV absorbance results. The results demonstrated that the band gap values agree with those of the literature.
- The electronic microscope results clarified that all the oxides synthesized at different calcination temperatures have particles in the nanometer scale (less than 100 nm). These results are in good agreement with those results obtained from the corresponding XRD results by using Scherrer equation.The photocatalytic activity results showed that all the prepared oxides by different methods have high efficiency for formic acid removal, as indicated by thedecrease of the TOC and the increase of the pH values of the treated solutions