1. Synthesis & Characterization of TiO2 &
doped TiO2 Nanostructures for application
in Dye Sensitized Solar Cell
Project Guide Project Student
Dr.Tom Mathews Jose Martina P
Scientific Officer (G) 13PGN02
SND Internal Project Guide
IGCAR- Kalpakkam Dr.V. Sri Devi
Co-ordinator
Center for NanoScience
Lady Doak College
Madurai

2. Outline of the work
• Synthesis of TiO2 nanotube powders by Electrochemical
anodization Technique
• Modification of the synthesized TiO2 by Nitrogen doping
• Characterization of the synthesized TiO2 using XRD, HRTEM,
FESEM and DRS

3. Introduction
Titania is a wide band gap semiconductor metal oxide.
Nano structures of this material has widespread application
in solar energy conversion .
Electrochemical anodization was found to be the easiest and
cost effective method for the synthesis of TiO2 nanotubes
By this technique powder nanotubes of TiO2 were
synthesized
The bandgap was modified by N-doping

4. Biological and chemical inertness
Non-toxicity
Low cost
Availability
Long term stability against photo and chemical
corrosion
AdvantagesTitania
Applications
 Photocatalysis (hydrogen generation and organic
destruction)
 Sensors
 Self cleaning properties
 Antibacterial action
 Photovoltaic devices

5. Motivation
To synthesize TiO2 nanotubes by electrochemical anodization
technique and to study the crystalline and morphological stability
for Dye Sensitized Solar Cell application

6. What is Solar Energy?
Energy produced by the sun
Clean, renewable source of energy
Harnessed by solar collection
methods such as solar cells
Converted into usable energy such as
electricity

7. Energy Demand
To overcome the demand solar cell is used

8. Photovoltaic Solar Cells
Generate electricity directly from
sunlight
2 Main types:
Single-crystal silicon (traditional)
•Widespread
•Expensive to manufacture
Dye-sensitized (“nano”)
•Newer, less proven
•Inexpensive to manufacture
•Flexible
•High power conversion
efficiencies
Silicon-based
solar cell
Dye-sensitized
solar cell

9. Synthesis of one dimensional TiO2 architectures
Nano architectures – Nanotubes, rods and wires more active due to
directionality and large surface area. Hence nanotubular Architectures of
TiO2 were preferred Nanotubular architectures
Nanotube powders
Electrochemical Anodization
Nanotube arrays
Rapid Breakdown anodization
Advantages of Electro chemical anodization
Cost effective
Simplest of all techniques
Aspect ratio tuning by changing the electrochemical
parameters

10. Chemical reaction involved…..
2Ti + 2H2O 2TiO2 + 4e + 4H+
Working Electrode: Ti foil
Counter Electrode: Platinum foil
 Electrolyte : 0.1M perchloric acid
 Applied voltage :11V
White powders of Titania ……
Synthesis of TiO2 powder nanotubes
Technique used …
Rapid break down
anodization

11. Synthesis of TiO2 nanotube arrays
Working Electrode: Ti foil
Counter Electrode: Platinum foil
 Electrolyte : 97 g of ethylene
glycol +0.5 g ammonium
fluoride +2.5 g of DI water
 Applied voltage :40V
Technique used …
Electrochemical
Anodization

12. TiO2 Doping
To overcome the disadvantage of tio2 dopants are
usedDopants modify nano-TiO2’s
effective range of light sensitivity
from the ultra-violet (UV) region to the visible light
region due to band gap tuning

13. 1. Photovoltaic Studies
Solar Cell Fabrication and testing of DSSC fabricated using TiO2 nanotube arrays on
Ti foils and FTO coated glasses
Dye loaded TiO2 on
FTO glass

Pt electrode
DSSC ready!!!!!!!
Taken for solar cell
performance studies
•Dye-0.5mM N 719 dye in acetonitrile
•Electrolyte- solaronix Iodolyte
Schematic of DSSC
A sandwitch structure made of two conducting electrodes with
a redox electrode filling the inter layer separation.
Exposure of light - excitation of the dye - injects electrons to
the CB of the oxide layer
Electron hope through the semiconductor and collected at the
collector electrode.
Electrons flow through the external circuit and reach to the
counter electrode
Reduce the oxidized form of the electrolyte.
13

14. DSSC MECHANISM
S + hν → S∗ (1)
S∗ → S+ + e− (TiO2)
3I- →I3
- + 2e−
S+ + e− → S
I3
− + 2 e− → 3 I−

15. RBA
Electrochemical synthesis routes provide an
attractive alternative to the standard methods
of synthesizing
nanomaterials. Electrochemical anodic
oxidation has been widely used to synthesize
TiO2 nanotubes on
titanium metal surface. Recently, an
anodization of Ti foil in an electrolyte
containing chloride or perchlorate
ions can produce high aspect ratio TiO2 NTs in
very short time (~ 50 µm in < 1 min), which the
main
advantage of this kind of anodization that
known as “rapid breakdown anodization”

16. TiO2 Nanostructures – Energy Related Applications
Dye Sensitized Solar Cell Hydrogen Generation by
water splitting
Counter Electrode Working electrode
Pt – Optimization
Electrochemical
Characterization
Ammonia
annealing
Electrochemical
anodization
Electrochemical
impedance spectroscopy
Mott Schotky plot
Studies
Synthesis of
1. TiO2 nanotube powders
2. N-doped TiO2 nanotube
powders
3. TiO2 nanotube arrays
4. N-doped TiO2 nanotube
arrays

17. Scanning Electron Microscopy
Transmission Electron Microscopy
X ray Diffraction
Raman Spectroscopy
Fourier Transform Infra Red Spectroscopy
X-ray Photoelectron Spectroscopy- compositional analysis
Photoluminescence
Ultraviolet and Visible Absorption Spectroscopy
Temperature Programmed Desorption Reduction Oxidation
Brunauer Emmet Teller adsorption method
Application:
Field Emission
Contact Angle
Photocatalytic Hydrogen Generation
Solar Cell Fabrication and testing
Morphology and structural characterization
Optical characterization
Chemi & Physisorption surface
area measurement
Characterization
17

18. Experimental Details
 Synthesis of TiO2 nanotubes by electrochemical
anodization.
 Annealing of the anodized samples at different
temperatures.
 Characterization by FESEM and XRD
 Surface wettability by studies by contact angle
measurements.

19. Conclusions
 Self aligned TiO2 nanotube arrays were synthesized on Ti
substrates by electrochemical anodization technique.
 The potentiostatic transients qualitatively revealed the
mechanism of nanotube formation
 Structural and morphological stability were revealed from
XRD and FESEM analysis.
 Shows very good surface wettability with solar cell indicates
its potential application in Dye sensitized solar cell.

20. Ongoing studies & Future plans……
 Characterization of TNTA on Ti substrates, TNTA on FTO
coated glasses and N doped TNTA using FESEM, TEM, XRD,
XPS, Micro Raman, DRS, FTIR,UV visible spectroscopy
 To investigate the DSSC performance of the synthesized TiO2
nanotube arrays photocat h2 gen by water splitting
 Study the effect of crystallinity on the solar cell performance of
the material