Junhui He

Publications (3)16.36 Total impact

• Article: Assembly of Graphene Nanosheets and SiO(2) Nanoparticles Towards Transparent, Antireflective, Conductive, and Superhydrophilic Multifunctional Hybrid Films.

  Jiayi Zhu, Ligang Xu, Junhui He
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  ABSTRACT: A new approach for the fabrication of transparent, antireflective, conductive and superhydrophilic multifunctional hybrid films through the layer-by-layer (LbL) assembly of reduced graphene oxide (RGO) nanosheets and SiO(2) nanoparticles is reported. The RGO nanosheets, SiO(2) nanoparticles and films were characterized by means of transmission electron microscopy, UV/Vis absorption spectrophotometry, Raman spectroscopy, atomic force microscopy, contact angle/interface system, and a four-point probe. It was found that the graphene/SiO(2) hybrid films exhibited a significant increase in transmittance as compared with RGO films. The optical, electronic and wetting properties of hybrid films could be manipulated by rational design of the film structure and variation of the cycle number of the LbL assembly. The obtained transparent, conductive, and superhydrophilic graphene/SiO(2) hybrid films showed excellent antireflective, antistatic, and antifogging behaviors. The remarkable performance could be attributed to the combination of electrical conductivity of RGO nanosheets and superhydrophilic antireflective surface derived from SiO(2) nanoparticles.
  Chemistry 10/2012; · 5.93 Impact Factor
• Article: Assembly and benign step-by-step post-treatment of oppositely charged reduced graphene oxides for transparent conductive thin films with multiple applications.

  Jiayi Zhu, Junhui He
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  ABSTRACT: We report a new approach for the fabrication of flexible and transparent conducting thin films via the layer-by-layer (LbL) assembly of oppositely charged reduced graphene oxide (RGO) and the benign step-by-step post-treatment on substrates with a low glass-transition temperature, such as glass and poly(ethylene terephthalate) (PET). The RGO dispersions and films were characterized by means of atomic force microscopy, UV-visible absorption spectrophotometery, Raman spectroscopy, transmission electron microscopy, contact angle/interface systems and a four-point probe. It was found that the graphene thin films exhibited a significant increase in electrical conductivity after the step-by-step post-treatments. The graphene thin film on the PET substrate had a good conductivity retainability after multiple cycles (30 cycles) of excessively bending (bending angle: 180°), while tin-doped indium oxide (ITO) thin films on PET showed a significant decrease in electrical conductivity. In addition, the graphene thin film had a smooth surface with tunable wettability.
  Nanoscale 05/2012; 4(11):3558-66. · 5.91 Impact Factor
• Article: Facile synthesis of graphene-wrapped honeycomb MnO2 nanospheres and their application in supercapacitors.

  Jiayi Zhu, Junhui He
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  ABSTRACT: Graphene-wrapped MnO(2) nanocomposites were first fabricated by coassembly between honeycomb MnO(2) nanospheres and graphene sheets via electrostatic interaction. The materials were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and thermogravimetric analysis. The novel MnO(2)/graphene hybrid materials were used for investigation of electrochemical capacitive behaviors. The hybrid materials displayed enhanced capacitive performance (210 F/g at 0.5 A/g). Additionally, over 82.4% of the initial capacitance was retained after repeating the cyclic voltammetry test for 1000 cycles. The improved electrochemical performance might be attributed to the combination of the pesudocapacitance of MnO(2) nanospheres with the honeycomb-like "opened" structure and good electrical conductivity of graphene sheets.
  ACS Applied Materials & Interfaces 02/2012; 4(3):1770-6. · 4.53 Impact Factor