Composition optimization of Co3−xFexO4/reduced graphene oxide nanohybrids as excellent electromagnetic wave absorption abilities

Highlights: • The composition optimization of Co_3−xFe_xO₄/RGO (x = 1.5, 2.25 and 2.5) were synthesized. • The Co_3−xFe_xO₄/RGO nanohybrids exhibit excellent microwave absorption properties. • Enhanced microwave absorbing mechanism was discussed in details. - Abstract: Through a simple hydrothermal process, we reported the synthesis of the composition optimization of Co_3−xFe_xO₄/reduced graphene oxide (RGO) nanohybrids for enhancing their electromagnetic (EM) wave absorption abilities. The results indicated the Co_3−xFe_xO₄/RGO had remarkably EM wave absorption performances in comparison with pure Co_3−xFe_xO₄, RGO and their counterpart mixed composites, which were attributed to their synergistic effects. The minimum reflection loss values for Co_3−xFe_xO₄/RGO (x = 1.5, 2.25 and 2.5) could reach up to ca. −66.9 dB, −47.3 dB and −27.7 dB, respectively, and their excellent microwave absorption properties were ascribed to the quarter-wavelength matching model. Moreover, compared with Co_3−xFe_xO₄/RGO (x = 2.25 and 2.5), the as-prepared Co_3−xFe_xO₄/RGO (x = 1.5) was found to exhibit an enhanced microwave absorption property, which could be attributed to its better dielectric and magnetic loss abilities, higher attenuation constant and impedance matching ratio. This optimized material is a very promising to be used as high performance microwave absorption material.