Preparation And Properties Of Core-shell Structured PANI-Co₃O₄ Nanocomposites

In recent years, the shortage of resources caused by fossil fuel consumption and environmental pollution including microwave pollution gradually pose a threat to human survival. For these problems, supercapacitors and microwave absorbing materials become research hotspots. And Co₃O₄ and PANI, as a typical transition metal oxide and a typical conductive polymer, respectively, have important applications in electrode materials of supercapacitor and microwave absorbing materials, but both of them have shortcomings and can not meet the requirements of practical application. To solve these problems and further improve the properties of the materials, herein, we prepared core-shell structured PANI-Co₃O₄ nanocomposites and tested the performance of PANI-Co₃O₄ nanocomposites as the electrode material of supercapacitor and the microwave absorbing material. Details are as follows:（1） Carbon Assisted method and in situ polymerization method were used to prepare core-shell structured PANI-Co₃O₄ nanocomposite. Characterization and analysis show that the average size of the nanocomposites is about 85 nm and the core Co₃O₄ with spinel structure has the size of about 55 nm. The shell PANI is amorphous. After PANI coating, the interface has important effects on the properties of the materials. Comparing with Co₃O₄ nanoparticles, the nanocomposites have narrower optical band gap, better UV-Vis absorption capacity and hydrophilic property.（2） Electrochemical performance of the PANI-Co₃O₄ electrode was tested on an electrochemical workstation. The results show that, the specific capacitance of the PANI-Co₃O₄ electrode is as high as 1184 F g-1 at a current density of 1.25 A g-1. After 1000 cycles, the capacitance retention is 84.9% at a current density of 12.5 A g-1. In addition, the PANI-Co₃O₄ electrode has good electrical conductivity and ion diffusion behavior.（3） Microwave absorption performance of the PANI-Co₃O₄ sample was measured using a vector network analyzer. The results indicate that, the maximum reflection of PANI-Co₃O₄ is up to-45.8 d B at 11.7 GHz with thickness of 2.5 mm. When the thickness is between 2-5.5 mm, the adsorption bandwidth of PANI-Co₃O₄ with the reflection loss below-10 d B reaches to 14.1 GHz.Compared with other studies about PANI-Co₃O₄, we combined nano-sized Co₃O₄ and nano-sized PANI by core-shell structure to generate a synergistic effect through the interface and parepared PANI-Co₃O₄ nanocomposites with narrower optical band gap and excellent hydrophilic property. The electrochemical properties of PANI-Co₃O₄ nanocomposites were significantly improved and the excellent microwave absorption performances were also obtained, which make PANI-Co₃O₄ nanocomposites be a multifunctional material and possible to achieve practical application and industrialization.