Adsorption and breaking of hazardous methyl mercury on hybrid structures of ionic liquids and ZnO nanoclusters

The detection and removal of the environmentally harmful substance methyl mercury (MeHg) have become an increasingly important issue due to its devastating effects on human tissues and organs. Hybrid systems of 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mim BF4) ionic liquid (IL) and (ZnO)n nanoclusters with n = 2-12 are potential candidates for adsorbing and sensing of MeHg. We are using density functional theory (DFT) calculations to better understand this functionality by calculating the bond orders, HOMO-LUMO energy gaps (Eg), and electronic projected densities of states (PDOS). With adsorption energy of-1.84 eV, IL/(ZnO)4 reveals the strongest interaction with MeHg among IL/(ZnO)n hybrid systems owing to Hg-O polarized covalent bonding. The spontaneity/feasibility of the adsorption process is validated by the negative values of DH and DG, which also suggest that the process is exother-mic and energetically favorable. The adsorption of MeHg molecules causes alterations in Eg, and PDOS, demonstrating the sensing ability of the hybrid structures. Increasing the alkyl chain length results in maximum adsorption energy of MeHg over the C10mim BF4/(ZnO)4 (-1.98 eV). Our results point the way to the implementation of multi-functional IL/(ZnO)n hybrid systems for sensing and adsorbing haz-ardous MeHg in the environment based on low-cost, rapid, and sensitive sensors.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The detection and removal of methyl mercury (MeHg) is crucial for environmental protection and human health. Hybrid systems of ionic liquid (IL) and nanoclusters have potential for adsorbing and sensing MeHg. Density functional theory (DFT) calculations reveal that IL/(ZnO)4 shows the strongest interaction with MeHg, and increasing the alkyl chain length enhances MeHg adsorption.