Multifunctional PAA- and PEG-modified Co3V2O8 nanoparticles for enhanced RhB degradation, OER activity, and antibacterial activity: experimental validation and computational insight

Abstract

Developing earth-abundant, cost-effective, sustainable and efficient multifunctional catalysts for the oxygen evolution reaction (OER), catalytic dye degradation, and antibacterial activity is extremely challenging. Herein, a novel ternary heterogeneous catalyst, polyacrylic acid/polyethylene glycol-cobalt vanadate nanoparticles (PAA/PEG-Co₃V₂O₈ NPs), was synthesized using a co-precipitation method. This study reported the multifunctionality of PAA/PEG-Co₃V₂O₈ in degrading RhB, enhancing OER activity, and inhibiting multiple drug-resistant Staphylococcus aureus (MDR S. aureus), with molecular docking analysis providing insights into binding interactions. The samples were comprehensively analyzed using an array of analytical techniques, including XRD, SAED, FTIR spectroscopy, UV-Vis spectroscopy, TEM, HRTEM, and EDS. The electrochemical activity of the prepared material was evaluated by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The optimized sample exhibited a maximum degradation of 96.34% in an acidic medium within 10 minutes and demonstrated minimal overpotentials of 270, 299, and 362 mV at 30, 50, and 100 mA cm⁻², respectively. The lowest Tafel slope and charge-transfer resistance indicated the superior OER performance. The optimized material showed a maximum inhibition zone of 8.25 ± 0.93 mm against MDR S. aureus. The bactericidal action of PAA/PEG-Co₃V₂O₈ NPs was further elucidated through molecular docking, which substantiated their role in the inhibition of topoisomerase II DNA gyrase and dihydrofolate reductase (DHFR) in S. aureus. These findings demonstrate the role of PAA and PEG in improving the overall activity of Co₃V₂O₈, yielding a pathway for fabricating an efficient, cost-effective, and sustainable material for environmental remediation and water-splitting applications.