Magnetic field assisted growth and reconstruction of Ti3C2Tx on Fe-Loaded loofah carbon for enhanced thin broadband microwave absorption

• Magnetic-assisted strategy builds heterointerfaces for enhanced microwave absorption. • Interfacial reconstruction yields defect-rich TiO 2 , boosting dielectric losses. • Minimum reflection loss reaches –32.9 dB with 3.2 GHz bandwidth at 2.8 mm. Biomass-derived porous carbons are promising lightweight microwave absorbers but often suffer from limited magnetic loss and weak interfacial polarization. In this work, a magnetic-field-assisted interfacial reconstruction strategy is proposed to construct multifunctional heterointerfaces in loofah-derived porous carbon. Iron ions were incorporated into the biomass scaffold to form iron-containing porous carbon, followed by the introduction and field-assisted reconstruction of titanium carbide precursors during thermal treatment. This process induces the formation of titanium carbide, defect-rich titanium oxide phases, and strongly coupled metal oxygen carbon interfaces within a hierarchical porous framework. The reconstructed heterostructure significantly enhances interfacial polarization, magnetic loss, and dielectric magnetic synergistic attenuation while improving impedance matching. As a result, MF&Fe-LPC composite achieves a minimum reflection loss of –32.9 dB and an effective absorption bandwidth of 3.2 GHz at a thickness of 2.8 mm. This study demonstrates an effective interfacial engineering route for designing thin and broadband microwave absorbers from biomass-derived carbon materials.