From molecular design to topological architecture: Ti-induced carbon nanowire networks in SiOC ceramics for high-performance electromagnetic wave absorption

Achieving lightweight and ultrabroadband electromagnetic (EM) wave absorption requires precise regulation across multiple scales; however, bridging molecular design with macroscopic architecture remains a significant challenge. Herein, a multiscale design strategy is proposed by integrating molecular-level precursor engineering, catalytic nanostructure evolution, and topological structural design. A titanium (Ti)-modified polysiloxane (PSO) precursor is constructed through the molecular incorporation of tetrabutyl titanate (TBT), which enables homogeneous Ti distribution within the polymer network and subsequent regulation of carbon evolution during pyrolysis. During pyrolysis, the tailored precursor chemistry drives the in-situ formation of catalytically active TiO x C y phases, which induce the transformation of free carbon from disordered nanoparticles into interconnected carbon nanowires (CNWs) networks. Coupled with a triply periodic minimal surface (TPMS) architecture enabled by additive manufacturing, the resulting CNWs-SiOC ceramics exhibit a synergistic enhancement in EM-wave attenuation. The optimized sample (ST-5) delivers a minimum reflection loss (RL min ) of −59.21 dB at 14.1 GHz with a thickness of 3.30 mm, along with an ultrabroad effective absorption bandwidth (EAB) of 9.20 GHz at 3.70 mm. The superior performance originates from the cooperative effects of improved impedance matching, enhanced conduction loss enabled by CNWs networks, and intensified interfacial polarization arising from abundant TiO x C y /SiOC heterointerfaces, together with multiple scattering within the TPMS framework. The proposed multiscale design strategy achieves lightweight SiOC ceramics with broadband EM-wave absorption through the synergistic effects of molecular precursor engineering, carbon-topology reconstruction, interfacial regulation, and TPMS architecture.