The impact of synthetic modifications on FeCo Prussian blue analogue and their consequential effects on the Fenton degradation of acetaminophen

The prolonged exposure to acetaminophen (ACT), one of the most used painkillers, has been shown to have adverse effects on human health. This study explores the impact of different synthetic modifications of an iron cobalt Prussian blue analogue (FeCo PBA) on the ACT degradation efficiency via Fenton-like reaction. Three synthetic modifications were performed, specifically through hydrothermal (FeCo PBA-HT), microwave (FeCo PBA-MW), and coprecipitation (FeCo PBA-Coppt) methods. FeCo PBA-HT exhibited the highest ACT degradation efficiency of 97 % within 60 min of the reaction as well as the highest kinetic rate constant. The degradation efficiencies were in the order FeCo PBA-HT > FeCo PBA-MW > FeCo PBA-Coppt. The effect of the synthetic modifications on the catalysts’ surface properties and chemical compositions were analyzed using FE-SEM, TEM, BET surface area analysis and XPS. Both the FE-SEM and TEM analysis revealed that FeCo PBA-HT particles were smaller compared to the FeCo PBA-MW and FeCo PBA-Coppt. The BET surface area analysis indicated that FeCo PBA-HT exhibited a surface area of 359.56 m 2 /g, the highest among the three. Furthermore, insights from the XPS analysis revealed a higher ratio of Fe 2+ : Fe 3+ and Fe: Co for the hydrothermal samples, correlating with the higher degradation efficiency. A plausible mechanism for the Fenton degradation of ACT by FeCo PBA-HT involves the initial formation of Fe-H 2 O 2 and Co-H 2 O 2 precursor complexes. The bimetallic nature of the catalysts facilitates a rapid and continuous cycle of Fe 2+ /Fe 3+ and Co 2+ /Co 3+ , enabling the efficient generation of reactive oxygen species. This process involves both direct H 2 O 2 activation and secondary pathways, such as the Haber-Weiss mechanism, to achieve effective Fenton degradation of ACT. Overall, this study presents an understanding on modifying and optimizing the synthesis processes of FeCo PBAs, while also dwelling to mechanistic aspects of ACT Fenton degradation. • FeCo PBA with varying particle sizes and surface area were synthesized. • FeCo PBA-HT exhibited rapid Fenton degradation efficiency of acetaminophen. • Influence of surface properties, and chemical composition on catalytic activity was explored. • Reactive radical species were identified to elucidate the degradation mechanism. • The synergistic effect of Fe and Co and the influence of radicals on ACT degradation was discussed.