Photo-thermal catalytic degradation of organophosphate simulant over Cu, Co, and Fe on titania

Abstract

Herein we demonstrate the degradation of organophosphate pesticide malathion in aerated alcohol over a tandem photo-thermal catalyst. TiO2-supported Cu, Co, and Fe was prepared by impregnation of metal-EDTA chelates or metal nitrates. Under UV irradiation, TiO2 generates H2O2 in situ (up to 1.8 ± 0.4 mmol/l) from dissolved O2 and alcohol, while the metals promote Fenton-like degradation reactions. The TOF of malathion degradation is maximum (11.9 ± 1.1 ks−1) for Cu/TiO2 at the highest metal dispersion, achieved by Cu-EDTA impregnation at low surface density (2.0 ± 0.3 atom/nm2). TOF of catalysts prepared from nitrates were at least 45% lower than those of catalysts prepared from chelates.

Keywords

• Photo-thermal catalysis
• Malathion
• Organophosphate neutralization
• H2O2 production
• Fenton chemistry