Preparation, characterization and performance of Z-scheme TiO2/WO3ZnO nanophotocatalyst, and photocatalytic application. Ref. No. SSTCRC060
Title:
Preparation, characterization and performance of Z-scheme TiO2/WO3ZnO nanophotocatalyst in the multicomponent synthesis of organic compounds and their photocatalytic applications in the degradation of environmental pollutants
Background:
The development of renewable energy sources is necessary to achieve a sustainable society. Photocatalysts are a group of catalysts that show good performance when exposed to light radiation. The reaction of photocatalysts takes place on the semiconductor surface. Photocatalyst technology can purify water and reduce certain pollutants and purify the air with the process of reducing concentration of harmful pollutants such as reducing NOx that comes from the combustion of fossil fuels such as coal and Gases, and indoor decontamination processes are used to remove volatile organic compounds.
The advantages of using photocatalyst compared to other common methods are:
1- It is a completely clean method and does not create any kind of pollution.
2- They have a low price and can be recycled and reused.
3- In most cases, photocatalysts are non-toxic.
4- They have high oxidation activity to carry out synthetic reactions in organic chemistry.
5- They have high chemical stability and do not decompose easily in the presence of light or water.
6- They can be activated with the help of ultraviolet light and in some cases with visible light.
7- They don't need to add another chemical substance and can perform the photocatalytic process alone in the presence of light.
8- They are generally compatible with the environment.
Research Progress:
In this project where we will study TiO2/WO3ZnO photocatalysts, we will synthesize photocatalysts using hydrothermal methods and then try to improve their catalytic and photocatalytic properties by coupling TiO2 with a semiconductor with a suitable and narrow bandgap. Finally, we examine the catalytic and photocatalytic efficiency of the resulting compounds in different synthetic reactions or in the removal of environmental pollutants.
In order to achieve the above goals, we will test different methods as follows and compare their final efficiency:
1- The use of WO3ZnO semiconductor with a very narrow bandgap to be composited with TiO2, which can be synthesized using the hydrothermal method with titanium peroxide, potassium hydroxide, silver nitrate and antimony trioxide based on the existing reported standard methods. Our investigations show that such compounds have a favorable band gap and are able to show a good photocatalytic role by using visible radiation.
2- Another common and relatively old method is to couple TiO2/WO3ZnO photocatalysts through a sonicate. Of course, this method is not very reliable and useful.
3- In another part of this project, we will try to simultaneously or asynchronously synthesize composites including semiconductor photocatalysts and check their catalytic or photocatalytic efficiency. For this purpose, in asynchronous method, we synthesize TiO2 photocatalyst and WO3ZnO photocatalyst separately and composite them together using Sonicate device. The simultaneous method is to add the ingredients of the second photocatalyst while mixing at the appropriate temperature while making the primary photocatalyst, and the desired composites are prepared at the same time.
Since many of the catalysts considered for this project are directly or indirectly among semiconductors, carrying out photocatalytic reactions for the degradation of environmental pollutants such as organic dyes and some pharmaceutical pollutants in aquatic environments using visible light or near ultraviolet will also be considered. In case of success, efforts will be made to investigate the above-mentioned photocatalytic reactions with natural sunlight and to improve the goals and results of the research project.
The advantages of using photocatalyst compared to other common methods are:
1- It is a completely clean method and does not create any kind of pollution.
2- They have a low price and can be recycled and reused.
3- In most cases, photocatalysts are non-toxic.
4- They have high oxidation activity to carry out synthetic reactions in organic chemistry.
5- They have high chemical stability and do not decompose easily in the presence of light or water.
6- They can be activated with the help of ultraviolet light and in some cases with visible light.
7- They don't need to add another chemical substance and can perform the photocatalytic process alone in the presence of light.
8- They are generally compatible with the environment.
Photocatalysts have the properties of self-cleaning, antibacterial, heat shielding, absorption and destruction of bad odors.
WO3/ZnO is a composite material that exhibits excellent photocatalytic properties. The photocatalytic activity of this material is attributed to the synergistic effect between its two components. Tungsten oxide is a visible light sensitive semiconductor with a band gap of 2.4 eV, while ZnO is a UV light sensitive semiconductor with a band gap of 3.3 eV. The combination of these two materials allows the absorption of visible and UV light and leads to an increase in photocatalytic activity. By adding TiO2 to this set, an S(Z)-Scheme with superior photocatalytic power can be designed. The mechanism of photocatalysis in this complex includes the production of electron-hole pairs due to light absorption. These electron-hole pairs can then react with water or organic compounds to generate reactive oxygen species (ROS) such as hydroxyl radicals (?OH) and superoxide radicals (O2??). These ROS can oxidize or degrade pollutants and lead to their removal from the environment.
The main applications that have been investigated for this technology include: removal and destruction of dyes, destruction of dangerous organic compounds, destruction of dangerous minerals such as cyanides, purification of heavy metals, decomposition of fungicides, herbicides and harmful insecticides, purification and disinfection.
In this project, we intend to use TiO2/WO3ZnO nanocomposite as a photocatalyst for the synthesis of some chromenes and destruction of some organic dyes.
The main goals of the project:
1- Fabrication of Z-cheme composites with two TiO2/WO3ZnO semiconductors
2- Investigating the level of photocatalytic activity of this type of composite compared to TiO2 and WO3ZnO photocatalyst alone.
3- Investigating the activity of TiO2/WO3ZnO photocatalyst as an antimicrobial or anticancer agent based on the conventional MTT method.
Cooperation Needs:
Having short visits from the Labs in China and Iran.
Cooperation to attain experiments.
Cooperation in writing of papers
Provide funds the same as that amount that the Iranian collaborator can earn from his country.
Benefits:
1. Forming a new strong research team
2. Having trips to China and Iran
3. Sharing students between the two countries
4. Publishing valuable papers
Outputs:
At least 2 ISI papers with IF point of 2-5 will be earned.