Study on the absorption properties of modified S+Co₃O₄/GNs by microregulation of surfactants with different properties

In this study, Co₃O₄/GNs composites were synthesized via a facile solvothermal method and subsequently modified using various surfactants (PVP, PEG, CTAB, and SDBS). The morphology, crystal structure, and microwave absorption properties of the composites were systematically investigated by optimizing the reaction time, surfactant concentration, and cobalt precursor dosage. Different surfactants induced diverse morphologies of Co₃O₄ nanoparticles. Notably, the PEG+ Co₃O₄/GNs composite exhibited the largest mesoporous size (21.60 nm) and microporous size (0.8073 nm), which created multiple reflection pathways for incident electromagnetic waves, thereby increasing energy dissipation channels and scattering centers. In terms of absorption performance, the PEG+Co₃O₄/GNs nanocomposite demonstrated exceptional characteristics at a thickness of 1.8 mm, featuring a remarkable minimum reflection loss (RL_min) of −52.87 dB and an effective absorption bandwidth (EAB) of 5.92 GHz at 2.1 mm. These superior microwave absorption properties can be attributed to its unique hierarchical porous structure and favorable impedance matching.