Showing papers by "Huazhong University of Science and Technology published in 2024"

Amino acids modified nanoscale zero-valent iron: Density functional theory calculations, experimental synthesis and application in the Fenton-like degradation of organic solvents

Abstract: To improve the adsorption and catalytic performance of heterogeneous Fenton-like catalysts for oil wastes, amino acids were used to modify nanoscale zero-valent iron ([email protected]0), which were applied in the Fenton-like degradation of organic solvents (tributyl phosphate and n-dodecane, named TBP and DD). Twelve amino acids, i.e., glycine (Gly), alanine (Ala), leucine (Leu), proline (Pro), phenylalanine (Phe), methionine (Met), cysteine (Cys), asparagine (Asn), serine (Ser), glutamic acid (Glu), lysine (Lys) and arginine (Arg), were selected and calculated by density functional theory (DFT). The optimized structure, charge distribution, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), interaction region indicator (IRI) isosurface map and adsorption energy of [email protected]0, [email protected]0−TBP and [email protected]0−DD were studied, which indicated that Fe is more likely to approach and charge transfer with -COO and -NH3 on the α-carbon of amino acids. There is strong attraction between Fe and –COO, and Van der Waals force between Fe and -NH3, respectively. In the interaction of [email protected]0 with TBP and DD, Van der Waal force plays an important role. [email protected]0 was synthesized in laboratory and characterized to investigate physicochemical properties. In Fenton-like degradation of organic solvents, the change of COD in water phase during the degradation process as well as the volume of the organic phase after the reaction were investigated. The results of calculations combined with experiments showed that Ser-modified Fe0 performed the best in these amino acids, with 98% removal of organic solvents. A possible catalytic mechanism was proposed in which amino acids acted a linking role between Fe and organic solvents, activating H2O2 to generate hydroxyl radicals for the degradation of organic solvents.