Photocatalytic degradation of Acephate, Omethoate, and Methyl parathion by Fe3O4@SiO2@mTiO2 nanomicrospheres

Abstract

A novel magnetic mesoporous nanomicrospheres Fe3O4@SiO2@mTiO2 were synthetized and characterized by a series of techniques including FE-TEM, EDS, FE-SEM, PXRD, XPS, BET, TGA as well as VSM, and subsequently tested as a photocatalyst for the degradation of Acephate, Omethoate, and Methyl parathion under UV irradiation. The well-designed nanomicrospheres exhibit a pure and highly crystalline anatase TiO2 layer, large specific surface area, and high-magnetic-response. Photocatalytic degradation of the three organophosphorus pesticides (OPPs) and the formation intermediates were identified using HPLC, TOC-Vcpn, IC, pH meter and GC–MS. Acephate, Omethoate, and Methyl parathion disappeared after 45min, 45min, and 80min UV illumination, respectively. At the end of the treatment, the total organic carbon (TOC) of the OPPs was reduced 80–85%. The main mineralization products were SO42−, NO3− and PO43− and Omethoate additionally formed NO2−. Based on the results, we proposed the photocatalytic degradation pathways for Acephate, Omethoate, and Methyl parathion.