A review on photocatalytic degradation of hazardous pesticides using heterojunctions

Contamination of natural resources by unwanted harmful chemical species is increasing day by day. After the use of pesticides in agricultural fields, some harmful residues are always left behind which become the major source of pollution. Among all the pollutants, toxic residues of agricultural pesticides cause numerous diseases as they directly pollute soil and water. Biodegradation by microorganisms is a natural process for eliminating pesticides whereas physical adsorption, membrane separation and advanced oxidation process are also used for removing pesticides. These methods are time consuming and unable to attain complete degradation of pesticide residues. Recently, various organic and inorganic compounds have been synthesized to achieve the targeted goal. Semiconductor materials have a tendency to generate electron-hole charge carriers which further contribute towards oxidation and reduction of pesticides. Large band gap value and fast recombination rate of charge carriers in basic semiconductor materials reduces their catalytic properties. Advancement in this field has been achieved by fabricating a composite by combination of two semiconductors having different band gap values. This newly formed composite exhibited excellent results for photocatalytic degradation of pesticides. The present review focuses on discussion of heterojunctions used for pesticide degradation and their catalytic efficiency in UV or visible radiations. Various investigations have proved that these synthesized materials are cost effective and efficient for utilization as photocatalysts for abating the pollution caused by pesticides.

Automated summary

Contamination of natural resources by unwanted harmful chemical species is on the rise, particularly due to pesticide residues causing pollution in soil and water. Current methods for removing pesticide residues are time-consuming and not fully effective, but newly synthesized organic and inorganic compounds as well as composite materials show promising results for degradation. Utilizing semiconductor materials with electron-hole charge carrier generation and band gap optimization can enhance the catalytic efficiency for pesticide degradation.