Measures of Central Tendency: Mean, Median and Mode
chapter1.pptx
1. The Principle and Application
of Photocatalysis
Teacher: Dr. Xin Yan
E-mail: xinyan@chd.edu.cn
2. 西安
Xi’an
• Chang’an University, or CHD, is a national key
university. Located in Xi’an City, Shaanxi
Province, CHD has two campuses and three
training bases, with a total area of 250 hectares.
7. Brief introduction of Course
Course name
The principle and application of photocatalysis
Course Type
Specialized and basic course for postgraduate students
Credits: 2
Teaching Hours: 32 hours (2 hours every week)
Exam method
Presentation and assignments （paper reports）
8. The basic knowledge and principles of photocatalytic
reaction are described in a comprehensive and systematic way.
The research progress and achievements of the design,
preparation and modification of photocatalyst are introduced.
The research methods of the physicochemical properties of
photocatalytic materials, the evaluation methods of
photocatalytic activity are summarized. The applications of
hydrogen, self-cleaning and organic matter conversion were
introduced in depth.
9. Through the study of this course, students can
master the basic theory and concept of photocatalytic
materials, learn how to analyze and solve the design of
materials, establish the basic scientific way of thinking,
and cultivate students' ability to use theoretical
knowledge and engage in scientific practice.
10. Students should master
the basic principles of photocatalytic materials and be familiar with the
photocatalytic reaction mechanism.
the research methods of physical and chemical properties of photocatalytic
materials and the evaluation methods of photocatalytic activity
understand the application of photocatalytic materials in environmental
purification, hydrogen production from water, self-cleaning and organic matter
conversion, etc.
train students to analyze the problems existing in photocatalytic materials and
have the ability to design high-performance photocatalytic materials.
11.
12. 1. Introduction to photocatalysis
2. TiO2 Nanomaterials a Future Prospect
3. TiO2-High Surface Area Materials Based Composite
Photocatalytic Nanomaterials for Degradation of pollutants:
A Review
4. Preparation, Characterization and Applications of Visible
Light Responsive Photocatalytic Materials
5. Silver Phosphate（Ag3PO4） Based Photocatalysis: A Brief
Review from Fundamentals to Applications
14. 6%
2%
17%
75%
Energy problems
10%
24%
40%
26%
CxHy + O2 H2O + CO2 + SO2 + NOx
coal oil
Natural
gas
etc
In China
In the world
煤
其他
the situation of energy mix and consumption
Unsustainable, Pollute the environment
oil
coal
Natural gas
etc
19. What is photocatalysis
Photocatalyst is a substance that can promote chemical reaction
without changing itself under the irradiation of
light. Photocatalytic reactions can promote the synthesis or
degradation of compounds . Photocatalytic reactions can convert
light energy into chemical reactions to produce catalysis.
20. Conduction band
valence band
Conduction band
Conduction band
valence band valence band
Band gap
Band gap
Conductor Semi-Conductor Insulator
Which material can be used as a
photocatalyst?
21. In a semiconductor, electrons was excitated from the valence band under light
irradiation. So photo generated electrons are formed in the conduction band and
photo generated holes are formed in the valence band. Photo generated electrons
have strong reducibility and can react with oxygen to obtain superoxide radicals.
Photo generated holes react with hydroxide ions to obtain hydroxyl radicals.
These are strong oxidizing free radicals that can degrade organic pollutants.
22. Question 1:
What can we do with photocatalysis?
Question 2:
What kind of enegry does photocatalysis use?
Question 3:
Which materials can be used as photocatalyst?
23. Influence factors of photocatalytic
reaction process
1.The absorption efficiency of light
How to improve the absorption
efficiency of light?
25. Eg=3.2 eV
Eg=2.7 eV
CB
VB
CB
VB
Eg=2.7 eV
CB
VB
UV light
Visible light
Visible light
Non-metal doped
Metal doped
Improved light absorption efficiency by ion doping
37. Inactivate cancer cells
Nano titanium dioxide was injected into the cancerous sites of mice
Before the light irradiation After the light irradiation
TiO2
38. Under UV light, water is completely
infiltrated on the titanium oxide
film. Therefore, coating a layer of titanium
oxide on the surface of bathroom mirror, car
glass and rearview mirror can play a role in
preventing fogging.
Application of anti-fogging and self-
cleaning coatings
40. Conclusion
Environmental problems and the energy crisis have created great challenges for scientist and
technologist at a global level. For the last 3-4 decades, major attention has been given for
photocatalysis to overcome these problems.
Photocatalysis is an effective catalytic process with potential applications in solving above
mentioned problems by degrading pollutants, reducing CO2 levels and water splitting,
respectively.
Till today, various photocatalytic materials, photocatalytic reactor, degradation of various
organic compound present in air and water have been studied and demonstrated. In spite of
significant research work carried out in the field of photocatalysis, there are several challenges
needing to be addressed such as enhancement in photocatalytic activity, development of
visible light activated photocatalysts, search of alternative photocatalytic materials, design and
development of photocatalytic reactors based on the irradiation source.
Editor's Notes
I've given you an electronic version of the course, and that's the main content, but not the whole thing
