Hang Luo,Zhong Wu,Xuefan Zhou,Zhongna Yan,Kechao Zhou,Dou Zhang
Carbon nano-materials e.g. graphene are widely utilized to prepare high-к dielectrics due to their low percolation threshold. However, composites incorporated with conductive carbon nano-materials usually suffer from high dielectric loss. In this work, a strategy is proposed to suppress the dielectric loss of graphene/P(VDF-HFP) composites using two-dimensional BaTiO 3 platelets. Large interfacial region is formed in the composites due to the hybrid fillers , which results with enhanced interfacial polarization . The BaTiO 3 platelets are aligned in the perpendicular direction to the surface of the composite film after the treatment of tape casting . These aligned BaTiO 3 platelets act as isolation belts to block the electron transportation path. In these contributions, composite with a high permittivity of 66.2 and suppressed dielectric loss of 0.048 are simultaneously obtained. This work provide a feasible route to prepare high performance dielectric composites.
Enzhu Lin,Ni Qin,Jiang Wu,Baowei Yuan,Zihan Kang,Dinghua Bao
Powder-form piezocatalysts suffer from poor recyclability and pose a potential threat of creating serious secondary pollution, which restrict their practical applications. Thin-film piezocatalysts, which not only exhibit good recyclability but also fully contact with solution, are believed to be one of the solutions to address these problems. In this work, the nanostructured BaTiO3 (BTO) thin films were fabricated by a facile hydrothermal method for their potential applications in piezocatalysis. The vertically standing BTO nanosheets grown on the top of TiO2 nanorod arrays exhibited superior piezocatalytic performance as well as piezo-electrochemical property. Given the different strain states between thin-film piezocatalyst and powder-form piezocatalyst, both the impact force of water and isostatic pressure are taken into consideration in finite element method (FEM) simulation. The FEM simulation shows that a stronger piezoelectric filed can be built in BTO nanosheets because of their easier deformation, and thus can lead to a higher piezocatalytic degradation efficiency. Our work presented here is expected to provide a potential route for the nanoengineering of thin-film piezocatalysts and clarify the catalytic mechanism for substrate-fixed piezocatalysts.