Selective photodegradation of 2,4-D pesticide from water by molecularly imprinted TiO2

Abstract

In this work, we present an effective approach, based on the combination of the molecular imprinting process and the photocatalysis, to perform a selective degradation of a specific and toxic pesticide. The TiO2 photocatalyst was imprinted through a simple and easy scaling-up synthesis method. The herbicide 2,4-dichlorophenoxyacetic acid (2,4D), a widespread pesticide in agriculture, was chosen as contaminant-target. The morphological, structural, optical, and textural properties of the TiO2-based materials were assessed by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), and N2 adsorption-desorption measurements, whereas the Fourier transform infrared spectroscopy (FTIR) characterization was performed to evaluate the effectiveness of the molecular imprinting process. The significant increase of the photocatalytic activity of the imprinted TiO2 with the corresponding pesticide-target, compared to bare TiO2, highlighted the synergism between the molecular imprinting and the photocatalysis. The good performance of the molecularly imprinted TiO2 photocatalyst allows to consider this approach as a promising strategy to obtain selective photocatalysts.