High Efficiency of Myclobutanil Adsorption by CTAB-zeolite Structures: Experimental Evidence Meets Theoretical Investigation

Pesticides effectively manage fungal diseases in fruits and vegetables; however, their toxicity poses significant environmental risks to human beings. Consequently, the chemical industry faces a daunting challenge in controlling or eliminating the presence of pesticides in the natural environment. The present work reports the synthesis of zeolitic materials with distinct structural properties (starting from the layered precursor PREFER and 3D-faujasite) and their use for the removal of the pesticide myclobutanil. The PREFER sample underwent two distinct treatments: external functionalization with CTAB and layers separation (delamination). On the other hand, external functionalization of the faujasite surface with different CTAB contents was performed. The results showed that the potentially delaminated PREFER sample (PREFER-CTAB-90ºC) performed better in removing the pesticide among all the samples due to the higher availability of CTAB on their exposed lamellae. In contrast, the samples with a double-layered arrangement of CTAB chains presented better pesticide removal performance in comparison with the samples with a single CTAB arrangement. DFT calculations were performed to elucidate the interaction mechanism occurring between myclobutanil and CTAB. The obtained results indicate that the adsorption of myclobutanil by two CTAB molecules is more efficient than a single CTAB; the calculated binding energy considering two CTAB molecules in the process was nearly four times larger than for a single CTAB. The theoretical data provided validation for the adsorbent performances, including a detailed discussion of molecular mechanisms (with and without solvent effects). This proof-of-principle study emphasizes the significant potential of CTAB-functionalized zeolite in removing myclobutanil. This represents an important advancement toward better understanding and harnessing the capabilities of this material for effective and efficient pesticide removal.