What is commonly used in photocatalysis?
18.3. Various photocatalysts such as ZnO, ZnS, CdS, SrO2, WO3 and Fe-TiO2 have been used for treatment of air pollutants. The most popular among them is TiO2 due to its low cost, high stability, environmental friendliness. It is a semiconductor which is used for photo-induced redox reactions for degradation of VOCs.
What is photocatalyst coating?
A photocatalyst coating is a coating that contains photocatalysts as ingredients. Photocatalysis is the complete cycle of converting light energy (from the sun or an electrical light source) into a chemical energy that’s transferred to water vapour to produce active oxygen species at the surface.
Is photocatalysis environmentally friendly?
Photocatalysis is a green, environmentally friendly, advanced oxidation process [2]. These charge carriers are subsequently utilized for various redox processes to facilitate decontamination of pollutants and bacteria.
What makes a good photocatalyst?
For an efficient photocatalyst, the band-gap energy should be smaller than 3 eV to extend the light absorption into visible region to efficiently utilize the solar energy.
How does photocatalyst work?
The substrate that absorbs light and acts as a catalyst for chemical reactions is known as a photocatalyst. When a photocatalyst is exposed to light of the desired wavelength (sufficient energy), the energy of photons is absorbed by an electron (e−) of valence band and it is excited to conduction band.
How does a photocatalyst work?
What are the types of photocatalysis?
The photocatalytic reactions can be categorized into two types on the basis of appearance of the physical state of reactants. Homogeneous photocatalysis: When both the semiconductor and reactant are in the same phase, i.e. gas, solid, or liquid, such photocatalytic reactions are termed as homogeneous photocatalysis.
How can the rate of degradation of the dye used be increased?
The degradation rate for the decomposition of the dye was found to increase with an increase in catalyst concentration, (Saquib and Muneer 2003).