Photocatalytic degradation of acetochlor by α-Fe2O3 nanoparticles with different morphologies in aqueous solution system

Abstract

Photocatalytic degradation technology is an important and promising method for complete elimination of toxic organics. In this study, the photocatalytic degradation of acetochlor using α-Fe2O3 nanoparticles under H2O2/UV system was studied with UV-Vis spectrophotometer and GCMS. The degradation rate was investigated on the effects of α-Fe2O3 morphology and dosage, initial acetochlor concentration, solution pH, and H2O2 dosage. The results showed that photocatalytic degradation efficiency could reach 91% by α-Fe2O3 with 200 mg/L hollow morphology at an initial acetochlor concentration, pH value, and H2O2 dosage of 50 mg/L, 7 and 40 μL, respectively. The photocatalytic reaction mechanism and degradation process of acetochlor by α-Fe2O3 were investigated and the degradation pathway of acetochlor was proposed. The oxidative attack involves NC bond connecting the aromatic ring with side chain, the nitrogen-containing side chain, chlorinated aliphatic to produce 1-methyl-3-ving-benzene, allyl-methyl-amine and 1-chloro-2-ethoxy-ethane. These intermediate products could be further oxidized to NO3−, CO2 and H2O. These findings provide new insights for the photocatalytic degradation of organic pollutants in the using α-Fe2O3 nanoparticles to achieve pollutant degradation.