NaCl-treated multiple carbon coating BaTiO nanoparticles towards enhancing dielectric properties

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 11; no. 31; pp. 173 - 1711
• Main Authors: Wang, Peng, Guo, Zihao, Sun, Zhihao, Du, Benli, Tian, Shaoyao, Qiu, Yu, Ding, Han, Qian, Lei
• Format: Journal Article
• Published: 10.08.2023
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d3tc01871g

Polymer-based dielectric composites have attracted extensive attention due to their wide applications in electrical systems. Herein, NaCl-treated multiple carbon coating BaTiO 3 nanoparticles (BT@N-C X NPs, where x represents the number of carbon-coating layers) were developed to regulate the carbon-shell thickness and optimize electrical properties to obtain excellent dielectric properties. A large dielectric constant (18.78@100 kHz) was observed along with a low dielectric loss (0.048@100 kHz) for BT@N-C 4 NPs at a content of 10 wt% in poly(vinylidene fluoride) (PVDF), which was about 2 times higher than that of the PVDF matrix (9.45@100 kHz). It was found that the graphitization of carbon shells improved after the NaCl treatment, attributed to the fact that NaCl as a nanoreactor inhibited the diffusion of disordered carbon atoms during the carbonization. Thus, the energy barrier of charge transport and electron hopping was reduced, resulting in a large charge flux and high polarization. The optimal carbon coating thickness was regulated to obtain an appropriate carbon content and larger interfacial polarization. Besides, the decrease of dielectric loss was due to the optimized charge transport paths, that is, the charges migrated on the surface of the carbon shell to avoid the formation of a conductive network. This work provides a novel design route for polymer-based composites to obtain a high dielectric constant with suppressed dielectric loss. NaCl-treated multiple carbon coating BaTiO 3 nanoparticles were produced and improved dielectric properties with low loss were obtained by the regulation of carbon shell thickness and the optimization of its electrical properties.