Self-template and in-situ polymerization strategy to lightweight hollow MnO2@polyaniline core-shell heterojunction with excellent microwave absorption properties.

The core-shell structure H-MnO 2 @PANI own excellent impedance matching characteristics (Figure b), and exist abundant interfaces that can produce strong interface polarization and enhance the loss of electromagnetic waves (Figure a), the minimum reflection loss is −52.06 dB (Figure b). The PANI bridge connects MnO 2 as a whole (Figure c), resulting in conductance loss dissipates electromagnetic waves and increases the effective absorption bandwidth to 4.56 GHz (Figure d). • The multi-interface structure MnO 2 @PANI is prepared by a mild self-template method. The surface modification enhanced the affinity of MnO 2 to AN, which made it possible to obtain the core-shell structure of MnO 2 @PANI successfully. • A series of MnO 2 -based products with multi-interface structure are obtained by simple self-template oxidation-etching strategy. The multi-interface structure is conducive to enhance the attenuation loss of polarization effect on electromagnetic wave. • RL min of H-MnO 2 @PANI is −52.06 dB at 8.48 GHz, and it has a broadband absorption of 4.56 GHz. Its excellent microwave absorption performance is attributed to the synergistic effect of conductivity loss, interface polarization and multiple reflection loss. Nowadays, high-frequency electromagnetic pollution makes the lightweight and high-efficiency absorption materials become the research hotspot. In this paper, the hollow structure MnO 2 @PANI microsphere composite was reasonably synthesized by self-template strategy and in-situ polymerization. Coating conductive polyaniline (PANI) on the modified surfaces of MnO 2 microsphere not only can improve the impedance matching and microwave absorption ability, but also solve the drawback of low loss intensity as well as narrow absorption band of pure MnO 2. The conductive polymer PANI conductance loss, MnO 2 -PANI multiple interfacial polarization and multiple reflection loss synergy endows hollow MnO 2 @PANI microsphere excellent microwave absorption performance. The RL min of hollow MnO 2 @PANI microsphere is −52.06 dB at 8.48 GHz and has a wide absorption of 4.56 GHz. Those positive results show that the pure dielectric MnO 2 @PANI microsphere material with a multi-interface hollow core-shell structure prepared from a template is a lightweight and efficient absorbent. [ABSTRACT FROM AUTHOR]