Improved photocatalytic decomposition of carbaryl pesticide in wastewater using ZnO nanorods

Abstract

This study explores the enhanced photocatalytic performance of ZnO nanorods (ZnO-R) for degrading the carbaryl pesticide (CB) in wastewater. For comparison, commercial ZnO (ZnO-C) was used to evaluate the differences in the photocatalytic decomposition of CB between ZnO-R and ZnO-C. The results regarding the material properties demonstrated that ZnO-R enhances CB removal performance due to its unique rod shape, which extends light absorption and improves electron-hole separation. The removal rates of the carbaryl pesticide from the aqueous solution using ZnO-R and ZnO-C were 98.2% and 87.3%, respectively. Besides, the presence of other pesticides had a more negative impact on the performance of CB than inorganic contaminants. The degradation rates of CB using ZnO-R in wastewater were 99.8%, 68.2%, and 21.7% under UV, solar, and visible light, respectively. In addition, the degradation mechanism of CB using ZnO-R under UV light was proposed based on the n-type photocatalysis process. This work provides a method for selecting a suitable type of ZnO photocatalyst to control pesticide residue pollutants that are commonly found in agricultural activities.