The principle of photocatalytic oxidation for deodorization
The photocatalytic oxidation method uses catalysts to accelerate the rate of liquid-phase oxidation and decomposition of odors.
The photocatalytic oxidation method using neodymium dioxide as a catalyst has a good removal effect on odor. In the past 20 years of research, it has been found that photocatalytic technology directly uses 02 in the air as an oxidant, under mild reaction conditions (room temperature, normal pressure), and has the ability to purify almost all pollutants. Common photocatalysts are mostly metal oxides or sulfides, such as TiC) 2, ZnO, ZnS, CdS, and PbS.
However, due to photo corrosion and chemical corrosion, TiC) 2 * ZnO has better practicality, with Ding 102 being the most widely used. TiO2 has the best comprehensive performance, with high photocatalytic activity (higher than ZnO), stable chemical properties, strong redox properties, insoluble, non-toxic, and low cost. It is the most widely studied and applied single compound photocatalyst. The essence of semiconductor photocatalysis is the redox reaction in photoelectric conversion. According to the electronic structure of semiconductors, when they absorb a photon with energy not less than their bandgap energy (? G), the electron (e2) will transition from the full valence band to the empty conduction band, leaving a positively charged hole (h+) in the valence band. Valence band holes have strong oxidizing properties, while conduction band electrons have strong reducing properties. They can directly interact with reactants and also react with other electron donors and acceptors adsorbed on the catalyst. For example, holes can oxidize H20, and electrons can reduce 02 in the air, generating H2() 2 The OH group and Hoy group have strong oxidation ability and can effectively oxidize odor pollutants, ultimately decomposing them into inorganic small molecules such as CO2 and H2O, achieving the goal of eliminating odor.
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