What is photocatalytic degradation?
A photocatalyst is defined as a substance which is activated by adsorbing a photon and is capable of accelerating a reaction without being consumed . Among AOPs, heterogeneous photocatalysis have been proven to be of interest due to its efficiency in degrading recalcitrant organic compounds.
What is photocatalytic process?
Photocatalysis is a process in which light energy is used to drive pairs of chemical reactions. Due to their activated state, the electron and hole perform chemical reduction and oxidation as though they were highly reactive reagents in a chemical reaction.
What are photocatalytic properties?
The photocatalytic properties of titanium dioxide have been widely studied over recent decades since the discovery of water photolysis by TiO2 electrodes in 1972. Titanium dioxide has three main crystal polymorphs; anatase, rutile and brookite and rutile is the most common as the metastable polymorph.
What is meant by dye degradation?
Dye degradation is a process in which the large dye molecules are broken down chemically into smaller molecules. The resulting products are water, carbon dioxide, and mineral byproducts that give the original dye its color. The color of the material becomes permanent.
Why TiO2 is used as photocatalyst?
Titanium dioxide (TiO2) has been widely used as a photocatalyst in many environmental and energy applications due to its efficient photoactivity, high stability, low cost, and safety to the environment and humans.
What is TiO2 used for?
Many cosmetic companies use titanium dioxide nanoparticles. Because of its bright whiteness, it is used in products such as paints, coatings, papers, inks, toothpaste, face powder, and food colouring.
Why is photocatalyst used?
A photocatalyst is a material which absorbs light to bring it to higher energy level and provides such energy to a reacting substance to make a chemical reaction occur.
Why do we degrade dyes?
Dye degradation is a process in which the large dye molecules are broken down chemically into smaller molecules. Dye molecules persist in the environment because many of them are not reactive towards light, acids, bases and oxygen. The color of the material becomes permanent.
Why methylene blue is used in photocatalysis?
Photocatalytic degradation oxidizes complex organic compounds into small molecular inorganic substances, such as carbon dioxide and water, under light. The reaction is thorough and causes no secondary pollution [1,2]. Methylene blue is used not only to dye paper and office supplies but also to tone up silk colors.
Is TiO2 harmful to humans?
Titanium dioxide (TiO2) is a natural oxide of the element titanium with low toxicity, and negligible biological effects.