Synthesis by coprecipitation of copper ferrite and its application in photochemical reactions.
herbicides, 2,4-D, copper ferrite, catalyst.
The increase in the consumption of pesticides, including herbicides, has caused a series of respect for their application and their consequences for humans and the environment. One of the most widely used herbicides in the world is 2,4-dichlorophenoxyacetic acid (2,4-D), however, its presence has been reported to be present in water bodies, causing impacts on the health of animals and humans. To degrade this contaminant, in this work copper ferrite (CuFe2O4) was synthesized using the coprecipitation method. The catalyst was studied in photodegradation reactions of the 2,4-D herbicide in aqueous solution, through heterogeneous photocatalysis with and without the addition of auxiliary oxidizing agents. The samples were was synthesized using the ratio 0.1 and 0.5 metal / base, using two types of salts, one with the Fe2+ ion and the other with the Fe3+ ion. A sample established by the Pechini method was synthesized for comparative purposes between the production methods. The catalysts were collected in a thermogravimetric test and calcined at 600°C. X-ray diffractograms were performed to determine the formation of the copper ferrite phase. A preliminary photocatalytic test was carried out to choose the catalyst with the best performance, the best sample being 0.1_Fe3+Cu, which with H2O2 degraded a large amount of 2,4-D. The parameters of the photocatalytic experiments were studied, such as: pH, concentration of catalyst, concentration of herbicide, concentration of oxidizing agent. The catalyst degraded 100% of the herbicide in 60 min of reaction. With the experimental data, following the law of the initiates, a law of speed was created that represents the model of the system. The law of speed followed a Langmuir-Hinshelwood kinetics and the reaction mechanism was studied, being possible that the catalyst obtained high performance in the degradation of 2,4-D with H2O2.