Preparation of CIP@TiO₂ composite with broadband electromagnetic wave absorption properties

Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder (CIP) with TiO₂ was designed. Given the TiO₂ coating, the Z of the CIP@TiO₂ composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO₂ was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO₂ composite was improved substantially, the minimum reflection loss reached −46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO₂ showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO₂ was about 400°C, whereas the uncoated CIP had an oxidation starting temperature of approximately 250°C. Moreover, the largest oxidation rate temperature of CIP@TiO₂ increased to around 550°C. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.