Study on the synthesis and structural characterization of spinel-structured Co3O4 metal oxide derived from metal-organic framework materials

Abstract

Spinel Co3O4 materials were successfully synthesized through the thermal decomposition of Co-BTC metal-organic frameworks prepared by hydrothermal and microwave-assisted methods. The structural characteristics and physicochemical properties of the materials were investigated by XRD, EDX, FTIR, SEM, and N₂ adsorption-desorption analyses. XRD and FTIR results confirmed the complete transformation of Co-BTC into pure spinel Co3O4 with high crystallinity, while EDX analysis indicated the complete removal of organic components after calcination. SEM images revealed that Co-BTC exhibited rod-like crystals, whereas Co3O4 consisted of near-spherical nanoparticles with sizes of approximately 50-60 nm, forming a porous structure. All samples exhibited mesoporous characteristics with type IV-H3 adsorption isotherms. The Co3O4 sample derived from the microwave-assisted MOF precursor achieved the highest specific surface area of 80.1 m2/g, which was significantly higher than that of the hydrothermal sample. The microwave-assisted method reduced the synthesis time to 60 min while improving the porous structure and process efficiency in accordance with green chemistry principles.