GCMC and electronic evaluation of pesticide capture by IRMOF systems.

Abstract

Environmental contamination by pesticides is a recurrent problem, and a way to minimize its impacts and provide the reduction of contaminants already in the environment is a challenge. In this context, porous materials such as metal-organic frameworks (MOFs) have gained prominence. MOFs can carry the pesticide when physically or chemically interacting with its pore sites, enabling pesticide capture. However, evaluating the best MOF to maximize the process is an important step that can be performed under computer simulation. This work used grand canonical Monte Carlo simulations to assess the interaction between glyphosate, atrazine, acephate, and dichlorodiphenyltrichloroethane pesticides with the structures of IRMOF-1, IRMOF-8, IRMOF-10, and IRMOF-16. These MOFs present several organic unit types, which generate different pore volumes with similar chemical environment. For glyphosate, atrazine, and acephate, a direct relationship was shown between the pore volume and the amount of captured pesticide, which is a direct contribution from the strong interaction between the pesticides. Higher pore volumes maximize glyphosate, atrazine, and acephate capture. Otherwise, for dichlorodiphenyltrichloroethane, the larger the pore volume, the smaller the amount of pesticide is loaded. The interaction between all pesticides and IRMOFs is mainly governed by van der Waals contribution, being more pronounced for glyphosate, atrazine, and acephate molecules.