Heterostructured SN@BAPC composite design via coordinated structure–morphology modulation: the mechanism of electromagnetic wave dissipation

Abstract

Based on a surfactant regulation strategy and structure optimization design, this study successfully prepared Sb₂S₃/N-doped porous carbon (SN@BAPC) composites with excellent electromagnetic wave (EMW) absorption performance. Through the synergistic process of carbonization and hydrothermal–pyrolysis, the structure–activity relationships of three surfactants (CTAB, PVP, and urea) on the morphology of Sb₂S₃ and the dielectric loss characteristics of the composites were systematically explored. Experiments show that by changing the surfactant to dynamically regulate the growth of Sb₂S₃ grains, the precise construction of rod-shaped and ginkgo-leaf-shaped heterostructures was achieved. Benefiting from the multi-scale synergistic effect, the optimized SN@BAPC exhibits excellent EMW performance: the rod-shaped sample has an RL_min of −42.32 dB (EAB of 3.12 GHz) at 1.7 mm, while the ginkgo-leaf-shaped sample, owing to a synergistic effect between the conductive network of the honeycomb-like porous carbon skeleton and the interfacial polarization effect of Sb₂S₃, achieves a loss of −38.36 dB and an ultra-wide EAB of 7.12 GHz at a thickness of 2.1 mm. Further theoretical analysis reveals that the gradient distribution of electromagnetic parameters induced by the surfactant improves the impedance matching properties, and the multi-level polarization relaxation formed by the 3D conductive network of N-doped porous carbon and the Sb₂S₃ heterojunction promotes the multi-mechanistic dissipation of electromagnetic energy. This research offers a highly significant reference for constructing microwave-absorbing materials (MAMs) with morphology modulation based on surfactants. It also confirms that antimony-based MAMs possess good potential value and broad application prospects for future applications.