Mangosuthu University of Technology (MUT)
Gumede N, Electrocatalysis of Endosulfan Based on Fe3O4- An Experimental and computational approach.pdf (4.64 MB)

Electrocatalysis of endosulfan based on Fe3O4: an experimental and computational approach

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journal contribution
posted on 2022-01-06, 08:29 authored by Gloria Uwaya, Njabulo Joyfull Gumede, Krishna Bisetty
The present work reports the electrocatalytic oxidation of the organochlorine pesticide endosulfan (EDS) using iron oxide (Fe3O4) nanoparticles synthesized from Callistemon viminalis leaf extracts. As a sensor for EDS, Fe3O4 was combined with functionalized multiwalled carbon nanotubes (f-MWCNTs) on a glassy carbon electrode (GCE). Cyclic voltammetry, electrochemical impedance spectroscopy, and the differential pulse voltammetry experiment were conducted to investigate the electro?chemistry of EDS on the GCE/f-MWCNT/Fe3O4 sensor. Based on optimized experimental conditions, the reports of analytical parameters show a limit of detection of 3.3 μM and an effective sensitivity of 0.06464 μA/ μM over a range of concentrations from 0.1 to 20 μM. With the proposed method, we were able to demonstrate recoveries between 94 and 110% for EDS determinations in vegetables. Further, a series of computational modeling studies were carried out to better understand the EDS surface adsorption phenomenon on the GCE/f-MWCNT/ Fe3O4 sensor. The highest occupied molecular orbital−lowest unoccupied molecular orbital (HOMO−LUMO) energy gap (−5.18 eV) computed by density functional theory (DFT) supports the layer-by-layer electrode modification strategy’s charge transfer and stability. Finally, transition state modeling was able to predict and confirm the mechanism of endosulfan oxidation.


Durban university of technology and Centre for high-performance computing (CHPC), Cape Town, South Africa