Non-uniform polarization boosted electromagnetic wave absorption with high efficiency and a broad frequency range

3-Aminobenzene sulfonic acid (mASA) has been co-polymerized into polyaniline (PANI) surface layers of ferrite nano particles by oxidative polymerization method. The sulfonic group of mASA anchored into PANI molecular have been employed as a dopant of PANI to partially substitute the dissociative dopant, hydrochloric acid (HCl). Owing to the constrained local distribution of mASA in PANI, the non-uniform polarization of PANI has been successfully stimulated by sulfonic acid doping. This results in various scattering loss modes and refined impedance matching in the synthesized ferrite/PANI nano-composite, which contributes to excellent absorbing properties with a high reflection loss of −56.42 dB and a broad effective absorption bandwidth of 3.8 GHz. The exhibited performances in microwave absorption are superior to most of ferrite-related composites. The explored strategy provides a novel way to tailor microwave absorbing composites to enhance their comprehensive microwave absorbing properties.