vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xvii
LIST OF FIGURES
xix
LIST OF ABBREVIATIONS / SYMBOLS
xxiv
LIST OF APPENDICES
xxx
INTRODUCTION
1
1.1
Background of the Research
1
1.2
Problem Statement
7
1.3
Research Objectives
8
1.4
Significance of the Study
8
1.5
Scope of the Study
8
LITERATURE REVIEW
10
2.1
Introduction
10
2.2
Carbon Spheres
12
2.2.1
Hydrothermal Carbonization of
Saccharides
2.2.2
13
The Mechanism of the Hydrothermal
Carbonization of Monosaccharide
15
viii
2.3
Hollow Structures
18
2.3.1
18
Characteristics of Hollow Structures
2.3.1.1 Large
Light
Harvesting
Efficiency
20
2.3.1.2 Low Density Material
2.3.2
Synthesis
Methods
of
21
Hollow
Structure
21
2.3.2.1 Template Method
22
(a) Hard Templating Method
22
(b) Soft-Templating Method
24
2.3.2.2 Template-free Method
25
(a) Ostwald Ripening
25
(b) Kirkendall Effect
26
(c) Oriented Attachment
Method
2.3.3
27
Advantages and Drawbacks of the
Synthesis Methods of Hollow
Structures
2.3.4
2.4
28
Application Fields of Hollow
Structures
29
2.3.4.1 Catalysis
29
2.3.4.2 Lithium-ion Batteries
30
2.3.4.3 Gas Sensors
31
2.3.4.4 Biomedical Materials
32
Metal Oxide Hollow Spheres
32
2.4.1
33
Titanium Dioxide
2.4.1.1 Structural Properties of
Titania
34
2.4.1.2 Optical and Electronic Properties of Titania
2.4.2
2.5
Hollow Titanium Dioxide Spheres
Physical and Chemical Properties of Gold
37
37
40
ix
2.6
Preparation Methods for Gold Supported
Catalysts
41
2.7
Physical and Chemical Properties of Silver
43
2.8
Preparation Methods for Silver Supported
2.9
2.10
Catalysts
44
Plasmon Optical Properties
45
2.9.1
46
Surface Plasmon Resonance (SPR)
Rattle-type Structures
2.10.1
2.10.2
49
Preparation Methods for Rattle-type
Structures
50
2.10.1.1 Usage of a Template
51
2.10.1.2 Encapsulation Sequence
51
2.10.1.3 Void Formation
52
Application of Rattle-type Structures
53
2.10.2.1 Rattle-type Nanoparticles
as Nanoreactors
53
2.10.2.2 Rattle-type Nanoparticles
as Drug Delivery Vehicles
54
2.10.2.3 Rattle-type Nanoparticles
as Lithium-ion Battery
Electrodes
54
2.10.2.4 Magnetic Solid-phase Ex
traction
55
2.10.2.5 High Performance Micro
wave Absorbers
56
2.10.2.6 Antimicrobial Nanorattles
56
2.11
Photocatalysis
58
2.12
Heterogeneous Photocatalysis
61
2.12.1
Semiconductor System
61
2.12.2
TiO2 as Photocatalyst
63
2.13
Pesticides
64
2.14
Classification of Pesticides
64
2.14.1
65
Insecticides
x
2.14.1.1 Lindane
65
2.14.1.2 Chlorpyrifos
66
2.14.1.3 Diazinon
67
Herbicides
68
2.14.2.1 Paraquat Dichloride
68
2.14.2.2 Atrazine
70
Fungicides
71
2.14.3.1 Imazalil Sulphate
71
CHARACTERIZATION TECHNIQUES
75
2.14.2
2.14.3
3
3.1
Field Emission Scanning Electron Microscopy
(FESEM)
75
3.2
Transmission Electron Microscopy (TEM)
76
3.3
Energy Dispersive X-ray Spectroscopy (EDX)
77
3.4
Fourier
Transform
Infrared
Spectroscopy
(FTIR)
77
3.5
X-ray Diffraction Spectroscopy (XRD)
78
3.6
Diffuse Reflectance Ultraviolet Visible Spectroscopy (DR UV–Vis)
79
3.7
Photoluminescence Spectroscopy (PL)
81
3.8
Brunauer-Emmett-Teller Surface Area Analysis (BET)
82
3.9
X-ray Fluorescence Spectroscopy (XRF)
82
3.10
Thermal Gravimetric and Differential Thermal
Gravimetric (TG–DTG)
4
83
SYNTHESIS AND CHARACTERIZATION OF
HOLLOW ANATASE TITANIUM DIOXIDE
85
4.1
Introduction
85
4.2
Experimental
86
4.2.1
Materials
86
4.2.2
Instruments
87
4.2.3
Preparation of Samples
88
xi
4.2.3.1 Synthesis of Carbon Spheres
under Hydrothermal
Conditions
88
4.2.3.2 Synthesis of Hollow Anatase
Titania Spheres
4.3
Results and Discussion
4.3.1
88
88
Influence of Synthesis Parameters on
the Physical Properties of Carbon
Spheres
4.3.2
Glucose and Fructose as Sacrificial
Templates
4.3.3
4.3.5
4.4
Summary
93
Comparison Between Glucose and
Fructose as Sacrificial Templates
4.3.4
88
94
Physicochemical Properties of
Carbon Spheres
95
4.3.4.1 Morphology
95
4.3.4.2 Chemical Composition
96
4.3.4.3 Functional Groups
97
4.3.4.4 Crystal Structure
98
4.3.4.5 BET Surface Area
98
4.3.4.6 Thermal Behaviour
99
Physicochemical Properties of
Hollow Titania
99
4.3.5.1 Morphology
99
4.3.5.2 Chemical Composition
101
4.3.5.3 Functional Groups
101
4.3.5.4 Crystal Structure
102
4.3.5.5 Band Gap Energy
103
4.3.5.6 BET Surface Area
105
4.3.5.7 Thermal Behaviour
105
106
xii
5
SYNTHESIS AND CHARACTERIZATION OF
GOLD
AND
SILVER
NANOPARTICLES
DEPOSITED ON THE EXTERNAL SURFACE
OF HOLLOW ANATASE TITANIA SPHERES
108
5.1
Introduction
108
5.2
Experimental
109
5.2.1
Materials
109
5.2.2
Preparation of Samples
109
5.2.2.1 Gold/Hollow Anatase Titania
Spheres
109
5.2.2.2 Silver/Hollow Anatase
Titania Spheres
5.3
109
Results and Discussion
5.3.1
110
Physicochemical
Gold/Hollow
Properties
Anatase
of
Titania
(Au/hollow TiO2)
110
5.3.1.1 Morphology
110
5.3.1.2 Chemical Composition
112
5.3.1.3 Functional Groups of
Au/hollow TiO2
114
5.3.1.4 Crystal Structure of
Au/hollow TiO2
115
5.3.1.5 Band Gap Energy
116
5.3.1.6 Photoluminescence (PL)
5.3.2
Properties
118
5.3.1.7 BET Surface Area
119
5.3.1.8 Elemental Analysis
119
Physicochemical Properties of
Silver/Hollow
Anatase
Titania
(Ag/hollow TiO2)
120
5.3.2.1 Morphology
120
5.3.2.2 Elemental Analysis
122
xiii
5.3.2.3 Functional Groups of
Ag/hollow TiO2
123
5.3.2.4 Crystal Structure of
Ag/hollow TiO2
124
5.3.2.5 Band Gap Energy
125
5.3.2.6 Photoluminescence (PL)
5.4
6
Properties
127
5.3.2.7 BET Surface Area
128
5.3.2.8 Elemental Analysis
128
Summary
129
SYNTHESIS AND CHARACTERIZATIONS OF
HOLLOW TITANIA SPHERES FUNCTIONALIZED WITH GOLD AND SILVER NANOPARTICLES INSIDE
131
6.1
Introduction
131
6.2
Experimental
132
6.2.1
Materials
132
6.2.2
Preparation of Samples
133
6.2.2.1 Encapsulation of Gold
or Silver Nanoparticles
in Carbon Spheres
133
6.2.2.2 Synthesis of Rattle-type
TiO2@Au
133
6.2.2.3 Synthesis of Rattle-type
TiO2@Ag
6.3
133
Results and Discussion
6.3.1
Physicochemical
134
Properties
of
TiO2@Au
134
6.3.1.1 Morphology
134
6.3.1.2 Chemical Composition
135
6.3.1.3 Functional Groups
136
6.3.1.4 Crystal Structure
138
xiv
6.3.1.5 Band Gap Energy
139
6.3.1.6 Photoluminescence
(PL) Properties
6.3.2
141
6.3.1.7 BET Surface Area
142
6.3.1.8 Elemental Analysis
143
6.3.1.9 Thermal Behaviour
143
Physicochemical
Properties
of
TiO2@Ag
145
6.3.2.1 Morphology
145
6.3.2.2 Elemental Analysis
147
6.3.2.3 Functional Groups
148
6.3.2.4 Crystal Structure
149
6.3.2.5 Band Gap Energy
150
6.3.2.6 Photoluminescence (PL)
6.4
7
Properties
152
6.3.2.7 BET Surface Area
153
6.3.2.8 Elemental Analysis
153
6.3.2.9 Thermal Analysis
154
Summary
155
PHOTOCATALYTIC
PERFORMANCE
OF
HOLLOW TiO2, TiO2@Ag, TiO2@Au, Ag/TiO2
AND Au/TiO2 IN PESTICIDES DEGRADATION
157
7.1
Introduction
157
7.2
Mechanism of Heterogeneous Photocatalysis
158
7.3
Approaches for Efficient Charge Separation
159
7.4
Metal/Semiconductor Heterostructure
7.5
7.6
Photocatalysts
160
Analytical Techniques
160
7.5.1
UV–Vis Spectrophotometry
160
7.5.2
Gas Chromatography (GC)
161
Experimental
162
7.6.1
162
Materials
xv
7.6.2
Instruments
162
7.6.3
Preparation of Standard Pesticide
Stock Solution
162
7.6.4
Calibration of Pesticide Solution
163
7.6.5
Photocatalytic Testing
164
7.6.5.1 Photocatalytic Degradation of
Paraquat Dichloride, Imazalil
Sulphate, Diazinon and
Atrazine
164
7.6.5.2 Photocatalytic Degradation of
γ-Lindane and Chlorpyrifos
7.7
164
Results and Discussion
165
7.7.1
Photodegradation Efficiency
165
7.7.2
Photocatalytic
Degradation
of
Paraquat
Dichloride,
Imazalil
Sulphate,
Diazinon,
Atrazine,
γ­Lindane and Chlorpyrifos
7.7.3
165
Factors Contributing to the Photocatalytic Efficiency Enhancement
167
7.7.3.1 Effect of Pesticides’
Chemical Structure on the
Photocatalytic Activity
167
7.7.3.2 Effect of Noble Metal on
Photocatalytic Efficiency
172
(a) Effect of Noble Metal’s
Type
on
the
Photo-
catalytic Efficiency
173
(b) Effect of Noble Metal’s
Location on the Photocatalytic Efficiency
7.7.4
Reasons
Behind
Photocatalytic
Ag/hollow TiO2
the
174
Improved
Performance
of
174
xvi
7.8
8
Summary
176
CONCLUSIONS AND SUGGESTIONS
178
8.1
Conclusions
178
8.2
Suggestions
180
REFERENCES
Appendices A - H
182
225 - 233
xvii
LIST OF TABLES
TABLE NO.
2.1
TITLE
PAGE
Previous studies on the reaction conditions used in the
19
preparation of carbon spheres
2.2
Previous studies and their findings for the preparation of
hollow titania spheres using hard template method
39
2.3
Some properties of Group 11 elements
45
2.4
Preparation techniques and application of noble metals
47
deposited on the TiO2 catalysts
2.5
Synthesis techniques of rattle-type noble metals (Ag and
57
Au)@TiO2
2.6
Band
gap
energy
and
wavelength
sensitivity
of
semiconductors
62
2.7
Physicochemical properties of lindane
66
2.8
Physicochemical properties of chlorpyrifos
67
2.9
Physicochemical properties of diazinon
68
2.10
Physicochemical properties of paraquat
69
2.11
Physicochemical properties of atrazine
70
2.12
Physicochemical properties of imazalil sulphate
72
2.13
Summary of work done for the degradation of pesticides
using heterogeneous photocatalysis process
4.1
Various sizes of carbonaceous spheres obtained from the
hydrothermal treatment of fructose with different conditions
4.2
89
Comparison of optimized reaction conditions using glucose
and fructose as precursors
4.3
73
95
Comparison between glucose and fructose as sacrificial
templates
95
xviii
4.4
Weight percentage of C and O of carbonaceous materials
obtained from the hydrothermal treatment of fructose
97
4.5
Weight percentage of Ti and O of hollow TiO2 spheres
101
5.1
Weight percentage of Ti, O and Au of Au/hollow TiO2
spheres
113
5.2
Elemental analysis by XRF for Au/hollow TiO2 spheres
120
5.3
Weight percentage of Ti, O and Ag of Ag/hollow TiO2
spheres
122
5.4
Elemental analysis by XRF for Ag/hollow TiO2 spheres
129
6.1
Chemical composition of the TiO2@Au from EDX analysis
136
6.2
Chemical composition of TiO2@Au spheres determined by
XRF analysis
143
6.3
Chemical composition of the TiO2@Ag from EDX analysis
148
6.4
Elemental analysis by XRF for TiO2@Ag spheres
154
7.1
Photodegradation efficiency of the five major groups of
pesticides used in this work after 7 h of irradiation using
different photocatalysts
7.2
166
Photodegradation efficiency and calculated intermediate
electronegativity of the five major groups of pesticides of
interest in the present study
170
xix
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Schematic presentation of the research plan
6
2.1
The dehydration and carbonization processes of (a)
glucose and (b) fructose under hydrothermal processing
2.2
Schematic Illustration of multi-reflections within the
spheres with solid, rattle-type and hollow structures
2.3
35
Schematic presentation of photocatalytic processes with
(a)
catalyzed
photoreaction
and
(b)
sensitized
photoreaction
2.5
58
Difference in concepts of (a) catalytic and (b)
photocatalytic reactions
2.6
21
Schematic of the crystalline structures of the two main
TiO2 forms, rutile and anatase
2.4
17
60
Configuration of the electronic bands of conductor,
semiconductor and insulator materials
62
2.7
Structural formula of lindane
65
2.8
Structural formula of chlorpyrifos
66
2.9
Structural formula of diazinon
68
2.10
Chemical structure of paraquat dichloride
69
2.11
Chemical structure of atrazine
70
2.12
Chemical structure of imazalil sulphate
71
4.1
SEM images of carbonaceous spheres obtained using
different concentrations of fructose as the carbon
precursor (a) 0.5 M, 160 °C, 5 h, magnification 10,000×
and (b) 0.7 M, 160 °C, 5 h, magnification 10,000×
91
xx
4.2
SEM images of carbonaceous spheres obtained by
hydrothermal carbonization of fructose samples (a) 0.5
M, 160 °C, 5 h, magnification 10,000× (b) 0.5 M, 170 °C,
5 h, magnification 10,000× and (c) 0.5 M, 180 °C, 5 h,
magnification 2000×
4.3
92
(a) Glucose’s structure and its six member ring cyclic
isomer glucopyranose (b) fructose’s structure and its five
member ring cyclic isomer fructofuranose
4.4
FESEM
image
of
carbon
spheres
93
prepared
by
hydrothermal method at 160 °C for 5 h, with fructose
concentration of 0.5 M, magnification 10,000×
96
4.5
EDX spectrum of the carbon spheres synthesized
96
4.6
FTIR
spectrum
of
carbon
spheres
prepared
by
hydrothermal method at 160 °C for 5 h, with fructose
concentration of 0.5 M
4.7
97
XRD pattern of carbon spheres prepared by hydrothermal
method at 160 °C for 5 h, with fructose concentration of
0.5 M
4.8
TGA curve of carbon spheres obtained under nitrogen
atmosphere at 25–800 °C
4.9
98
99
FESEM images of hollow TiO2 spheres, magnification
5000×. The white arrows show broken spheres revealing
the hollow structure inside, magnification 25,000×
4.10
100
(a) TEM image of hollow anatase TiO2 spheres prepared
by template method and (b) HRTEM image of the
selected particle
100
4.11
EDX spectrum of hollow TiO2 spheres
101
4.12
FTIR spectra of (a) carbon spheres prepared by
hydrothermal method and (b) hollow TiO2 spheres
4.13
XRD patterns for (a) ICDD No. 01-086-1157 for anatase
TiO2 and (b) hollow anatase TiO2 spheres
4.14
102
103
DR UV–Vis spectra for (a) commercial TiO2 and (b)
hollow TiO2
104
xxi
4.15
Band gap evaluation for linear dependence of (F(R∞).hv)½
versus photon energy for (a) commercial TiO2 and (b)
hollow TiO2
105
4.16
TG–DTG curves of hollow anatase TiO2 spheres
106
5.1
Experimental procedure for the preparation of Au/hollow
TiO2 spheres
5.2
110
FESEM images of the (a) hollow TiO2, magnification
25,000× and (b) Au/hollow TiO2 calcined at 300 °C,
magnification 50,000×
5.3
111
TEM images of (a) hollow anatase TiO2, (b, c) Au/hollow
anatase TiO2 and (d, e) HRTEM images of Au/hollow
anatase TiO2 calcined at 300 °C
112
5.4
EDX spectrum of Au/hollow TiO2 spheres
113
5.5
EDX mapping of Au/hollow TiO2 spheres
114
5.6
FTIR spectra of (a) hollow TiO2 and (b) Au/hollow TiO2
spheres
115
5.7
XRD pattern of Au/hollow anatase TiO2
116
5.8
DR UV–Vis spectra of (a) commercial TiO2, (b) hollow
TiO2 and (c) Au/hollow TiO2
5.9
117
(F(R∞).hν) 1/2 versus hν plot for band gap evaluation of (a)
commercial TiO2, (b) hollow TiO2 and (c) Au/hollow
TiO2 photocatalysts
5.10
Photoluminescence spectra of (a) hollow TiO2 and (b)
Au/hollow TiO2
5.11
118
119
FESEM images of (a) hollow TiO2, magnification
25,000× and (b) Ag/hollow TiO2 calcined at 300 °C,
magnification 75,000×
5.12
121
TEM images of (a) hollow anatase TiO2, (b) Ag/hollow
anatase TiO2 and (c, d) HRTEM images of Ag/hollow
anatase TiO2
121
5.13
EDX spectrum of Ag/hollow TiO2 spheres
122
5.14
EDX mapping of Ag/hollow TiO2 photocatalyst
123
xxii
5.15
FTIR spectra of (a) hollow TiO2 and (b) Ag/hollow TiO2
particles
5.16
XRD pattern of Ag/hollow TiO2 in the 2θ region of 10–
90°
5.17
125
DR UV–Vis spectra of (a) commercial TiO2, (b) hollow
TiO2 and (c) Ag/hollow TiO2
5.18
124
126
Band gap evaluation for linear dependence of (F(R∞).hv)½
versus photon energy (hν) for (a) commercial TiO2, (b)
hollow TiO2 and (c) Ag/hollow TiO2
5.19
Photoluminescence spectra of (a) hollow TiO2 and (b)
Ag/hollow TiO2
6.1
127
128
(a) SEM image of C/Au spheres, magnification 20,000×
and (b) FESEM image of rattle-type TiO2@Au calcined
at 600 °C, magnification 10,000×
6.2
134
(a) TEM and (b) HRTEM images of rattle-type TiO2@Au
calcined at 600 °C
135
6.3
EDX spectrum of TiO2@Au particles
136
6.4
FTIR spectra of (a) C/Au spheres prepared by
hydrothermal method, (b) hollow TiO2 and (c) rattle-type
TiO2 @Au calcined at 600 °C
137
6.5
XRD pattern of rattle type TiO2@Au calcined at 600 °C
138
6.6
DR UV–Vis spectra of (a) commercial TiO2, (b) hollow
TiO2 and (c) TiO2@Au
6.7
140
Band gap evaluation for linear dependence of (F(R∞).hv)½
versus photon energy for (a) commercial TiO2, (b) hollow
TiO2 and (c) TiO2@Au
6.8
141
Photoluminescence spectra of (a) hollow TiO2 and (b)
TiO2@Au samples
142
6.9
TG–DTG curves of the C/Au
144
6.10
TG–DTG curves of the TiO2@Au calcined at 600 °C
145
6.11
FESEM images of TiO2@Ag calcined at 600 °C,
magnification 50,000×
146
xxiii
6.12
(a) TEM image of TiO2@Ag sphres prepared by template
method and (b) HRTEM image of the selected particle
147
6.13
EDX spectrum of TiO2@Ag sample
147
6.14
FTIR spectra of (a) C/Ag spheres prepared by
hydrothermal method, (b) hollow TiO2 and (c) TiO2@Ag
calcined at 600 °C
149
6.15
XRD pattern of TiO2@Ag calcined at 600 °C
150
6.16
DR UV–Vis spectra for (a) commercial TiO2, (b) hollow
TiO2, (c) TiO2@Ag and the enlarged part in the region of
400–700 nm (inset)
6.17
151
½
Band gap evaluation for linear dependence of (F(R∞).hv)
versus photon energy for (a) commercial TiO2, (b) hollow
TiO2 and (c) TiO2@Ag
6.18
152
Photoluminescence spectra of (a) hollow TiO2 and (b)
TiO2@Ag
6.19
153
TG–DTG curves of (a) C/Ag spheres and (b) TiO2@Ag
calcined at 600 °C
7.1
Schematic
of
the
155
general
mechanistic
steps
in
heterogeneous photocatalysis on TiO2
7.2
159
Photoluminescence spectra of (a) Ag/hollow TiO2 and (b)
TiO2@Ag
175
xxiv
LIST OF ABBREVIATIONS / SYMBOLS
A
-
Absorbance
Ag
-
Silver
AgNO3
-
Silver nitrate
Al2O3
-
Aluminum oxide
AOP
-
Advanced oxidation process
atm
-
Atmosphere
Au
-
Gold
a.u.
-
Arbitrary unit
b
-
Path length of the sample
BaSO4
-
Barium sulphate
BET
-
Brunauer Emmet Teller
BHC
-
Benzene hexachloride
c
-
Concentration
C
-
Carbon
C0
-
Concentration of the solution before irradiation
CB
-
Conduction band
CeO2
-
Cerium(IV) oxide
CH4
-
Methane
CO2
-
Carbon dioxide
CO
-
Carbon monoxide
Co
-
Cobalt
(CO(NH2)2
-
Urea
CoO
-
Cobalt(II) oxide
Co3O4
-
Cobalt(II,III) oxide
Cr2O3
-
Chromium(III) oxide
CS
-
Carbon sphere
xxv
CTAB
-
Cetyltrimethylammonium bromide
Ct
-
Concentration of the solution after time t
CVD
-
Chemical Vapour Deposition
Cu
-
Copper
Cu kα
-
X-ray diffraction from copper kα energy levels
Cu2O
-
Copper(I) oxide
DMF
-
N,N-Dimethylmethanamide (Dimethylformamide)
DP
-
Deposition-precipitation
DTG
-
Differential Thermal Gravimetric
DR UV–Vis
-
Diffuse reflectance Ultraviolet–Visible
ECD
-
Electron capture detector
EtOH
-
Ethanol
e-
-
Electron
e-CB
-
Electron in conduction band
EDX
-
Energy Dispersive X-Ray Spectroscopy
EG
-
Ethylene glycol
e.g.
-
For example
Eg
-
Band gap energy
EF
-
Fermi energy
EM
-
Electromagnetic
EPA
-
Environmental Protection Agency
et al.
-
And others (Latin: et alia)
etc.
-
And the others (Latin: et cetera)
α-Fe2O3
-
Iron(III) oxide (Hematite)
FESEM
-
Field Emission Scanning Electron Microscopy
FESEM-EDX
-
Field Emission Scanning Electron Microscopy and Energy
Dispersive X-Ray Spectroscopy
FTIR
-
Fourier Transform Infrared
FWHM
-
Full width at half maximum
Ga2O3
-
Gallium(III) oxide
GaN
-
Gallium nitride
GC
-
Gas Chromatography
GC-µECD
-
Gas Chromatography Microelectron Capture Detector
xxvi
h+
-
Holes
h+VB
-
Positive hole in valence bond
H2
-
Hydrogen
HAuCl4.3H2O -
Chloroauric acid trihydrate
α­HCH
-
α­hexachlorocyclohexane
β­HCH
-
β­hexachlorocyclohexane
HCl
-
Hydrochloric acid
HDP
-
Homogeneous deposition–precipitation
He
-
Helium
HMF
-
5-hydroxymethyl-2-furaldehyde
H2O
-
Dihydrogen monoxide
H2O2
-
Hydrogen peroxide
HOMO
-
Highest occupied molecular orbital
hv
-
Energy (photon)
HRTEM
-
High Resolution Transmission Electron Microscopy
ID
-
Identification
i.e.
-
That is (Latin: id est)
IE
-
Ionization energy
ICDD
-
International Centre for Diffraction Data
In2O3
-
Indium(III) oxide
IUPAC
-
International Union of Pure and Applied Chemistry
KBr
-
Potassium bromide
K–M
-
Kubelka-Munk
KOW
-
Octanol–water distribution coefficient
La2O3
-
Lanthanum(III) oxide
LD50
-
Median lethal dose
LUMO
-
Lowest unoccupied molecular orbital
LSPR
-
Localized surface plasmon resonance
Lu2O3
-
Lutetium(III) oxide
MB
-
Methylene blue
MgO
-
Magnesium oxide
Mn3O4
-
Manganese(II,III) oxide
MO
-
Methyl orange
xxvii
N2
-
Molecular nitrogen
NaOH
-
Sodium hydroxide
NH4OH
-
Ammonium hydroxide
NiO
-
Nickel(II) oxide
O2
-
Oxygen
OCPs
-
Organochlorine Pesticides
OPPs
-
Organophosphorus Pesticides
O2-
-
Peroxo
O2-
-
Oxide ion
OH
-
Hydroxyl
•OH
-
Hydroxyl radical
OH-
-
Hydroxyl ion
P25
-
Comercial titanium dioxide
Pd
-
Palladium
pH
-
Acidity or basicity measurement
PL
-
Photoluminescence
i-PrOH
-
2-Propanol
PSA
-
Poly(styrene-methyl acrylic acid)
Pt
-
Platinum
PVP
-
Polyvinylpyrrolidone
R
-
Reflectance
R2
-
Linear least square
SAED
-
Selected area electron diffraction
Sb
-
Antimony
SEM
-
Scanning Electron Microscopy
SEEM
-
Sanderson electronegativity equivalence method
Sint
-
Sanderson intermediate electronegativity
SiO2
-
Silica
Sn
-
Tin
SnO2
-
Tin(IV) oxide
SPR
-
Surface plasmon resonance
T
-
Transmittance
T
-
Temperature
xxviii
t
-
Time
TBOT
-
Titanium(IV) buthoxide
TBT
-
Tetrabutyl titanate
TEM
-
Transmission Electron Microscopy
TEOS
-
Tetraethyl orthosilicate
TEOT
-
Titanium(IV) ethoxide
Ti
-
Titanium
Ti4+
-
Titanium ion
TiCl4
-
Titanium tetrachloride
TiF4
-
Titanium tetrafluoride
TiO2
-
Titanium dioxide
TGA
-
Thermal Gravimetric Analysis
TG–DTG
-
Thermal Gravimetric and Differential Thermal Gravimetric
TTEAIP
-
Titanium-(triethanolaminato) isopropoxide
TTIP
-
Titanium(IV) isopropoxide
UV
-
Ultraviolet
UV–Vis
-
Ultraviolet–Visible
V
-
Volume
v
-
Wavenumber
VB
-
Valence band
via
-
By way of (Latin: viā)
vs
-
Versus
WO3
-
Tungsten trioxide
wt %
-
Weight percentage
XRD
-
X-Ray Diffraction
XRF
-
X-ray Fluorescence Spectroscopy
Z
-
Atomic number
ZnO
-
Zinc oxide
ZnS
-
Zinc sulphide
ZrO2
-
Zirconium(IV) oxide
A
-
Absorbance
α
-
Absorption coefficient
D
-
Crystal size
xxix
h
-
Planck constant
λ
-
Wavelength
θ
-
Theta (Bragg angle)
~
-
Approximately
γ
-
Gamma
η
-
Percent degradation
R∞
-
Diffuse reflectance
s
-
Scattering factor
ε
-
Molar absorptivity
xxx
LIST OF APPENDICES
APPENDIX
A
TITLE
PAGE
Calibration graph of standard pesticides studied
using GC–µECD
225
B
Standard calibration curve of chlorpyrifos
226
C
Calibration graph of standard pesticides studied
using UV–Vis spectrophotometer
227
D
Standard calibration curve of imazalil sulphate
228
E
Standard calibration curve of diazinon
229
F
Standard calibration curve of atrazine
230
G
Crystallite size calculation
231
H
List of publications and conferences
232