Constructing BaTiO3/TiO2@polypyrrole composites with hollow multishelled structure for enhanced electromagnetic wave absorbing properties

BaTiO 3 /TiO 2 @polypyrrole (PPy) composites with hollow multishelled structure (HoMS) were constructed to enhance the electromagnetic wave absorbing properties of BaTiO 3 -based absorbing material. BaTiO 3 /TiO 2 HoMSs were prepared by hydrothermal crystallization using TiO 2 HoMSs as template. Then, FeCl 3 was introduced to initiate the oxidative polymerization of pyrrole monomer, forming BaTiO 3 /TiO 2 @PPy HoMSs successfully. The electromagnetic wave absorbing properties of BaTiO 3 /TiO 2 HoMSs and BaTiO 3 /TiO 2 @PPy HoMSs with different shell number were investigated using a vector network analyzer. The results indicate that BaTiO 3 /TiO 2 @PPy HoMSs exhibit improved microwave absorption compared with BaTiO 3 /TiO 2 HoMSs. In particular, tripled-shelled BaTiO 3 /TiO 2 @PPy HoMS has the most excellent absorbing performance. The best reflection loss can reach up to −21.80 dB at 13.34 GHz with a corresponding absorber thickness of only 1.3 mm, and the qualified absorption bandwidth of tripled-shelled BaTiO 3 /TiO 2 @PPy HoMS is up to 4.2 GHz. This work paves a new way for the development of high-performance composite microwave absorbing materials.