Photocatalytic Degradation of Bentazon Pesticide by a Fe2O3-TiO2 Composite Catalyst Irradiated by UVA, UVB, and Natural Light

Abstract

Environmental pollution by contaminants of emerging concern, among these various pesticides, has been a concern of environmentalists and scientists around the world. Thus, efforts to mitigate the impacts of these substances have been carried out, and the use of advanced oxidation processes, such as photocatalysis, is an alternative. This work sought to synthesize a composite photocatalyst based on iron oxides and titanium dioxide to assess its applicability in degrading the herbicide bentazon (BTZ) by a lamp that simulates the solar spectrum (visible, ultraviolet A and ultraviolet B) and sunlight. Photocatalytic degradation reached 51% in 120 min with a rate constant k = 0.0058 min−1 when a UV-Vis lamp of 300 W was used. The applicability was demonstrated under sunlight radiation, reaching 38% degradation of a bentazon solution (4.1 × 10−4 mol L−1) after 320 min. TiO2 and Fe2O3 were synthesized similarly but showed no degradation under the same conditions. Thus, Fe2O3-TiO2 is an inexpensive and non-toxic material capable of efficiently conducting the photocatalytic degradation of organic compounds, such as the bentazon herbicide.