were successfully synthesized by a hydrothermal method. A precursor
solution was prepared by dissolving FeCl3·6H2O (13.51 g, 2 mol) and CoCl2·6H2O (5.94
g, 1 mol) separately in 30 mL of distilled water. The two solutions
were then combined under continuous stirring, and glycerol (0.078
M) was slowly introduced. The pH of the resulting solution was carefully
maintained at ∼12.0 through the controlled addition of dilute
sodium hydroxide. Following the formation of a brown precipitate,
the entire mixture was further stirred for 30 min before being transferred
to a Teflon-lined autoclave. The autoclave was sealed and subjected
to hydrothermal treatment in an oven set at 180 °C for a duration
of 6 h. After the mixture cooled, the black precipitate was separated
through centrifugation, subjected to multiple washes with distilled
water to eliminate chloride ions, and subsequently dried at 80 °C
overnight. The resulting dried materials were securely stored in airtight
containers for future utilization.