Synthesis of FeCo nanoparticles
First, FeO(OH) and Co3O4 in appropriate amount were dissolved in Trioctylamine (TOA), then the mixture was loaded into a flask and dehydrated at 160 °C for 2 h under a flow of argon. Afterward, the mixture was quickly heated to 370 °C while vigorous stirring is maintained using a mechanical stirrer. Next, the product was cooled to room temperature and collected by centrifugation at 10,000 rpm. Finally, the product washed with hexane and ethanol, and dried under vacuum to obtain FeCo nanoparticles (FeCoNPs).