Shuang Cui

Supramolecular Helix of an Amphiphilic Pyrene Derivative Induced by Chiral Tryptophan through Electrostatic Interactions

An amphiphilic pyrene derivative (PyDNH3) bearing positively charged ammonium cations has been synthesized and characterized. Self-assembly of PyDNH3 in the presence of chiral tryptophan derivatives was investigated in ethanol/water by optical and chiroptical spectra, indicating the formation of helical aggregates. Scanning electron microscope (SEM) images showed the formation of ring-shape structures.

Controlled growth and field emission properties of CuS nanowalls

Vertically oriented CuS nanowalls supported on a copper substrate have been synthesized through a facile method involving an inorganic vapour–solid phase reaction. The CuS nanowalls were well connected to form an extended network. The shapes of the CuS nanostructures could be controlled by adjusting the reaction conditions such as the reaction temperature and the flow rate of argon gas. The crystallinity of the nanowalls was investigated by XRD and their morphological features were characterized by FESEM. Both TEM and SAED analyses revealed that the nanowalls are single-crystalline. The field emission properties of the CuS nanowalls were investigated. The turn-on field and current density of the CuS nanowalls are comparable to those of many other semiconductor nanomaterials, which suggests that the CuS nanowalls may have potential applications in the vacuum microelectronics industry.

Fabrication of large-area hybrid nanowires arrays as novel field emitters

A hybrid nanomaterial composed of ZnO nanoparticles (NPs) and CuTCNQ (copper 7,7,8,8-tetracyanoquinodimethane) nanowires (NWs) was successfully fabricated in a simple solution method. The electron field emission properties of the hybrid NWs were dramatically improved over those of raw CuTCNQ NWs. The maximum current density of ZnO-CuTCNQ NWs was six times that of the CuTCNQ NWs array. Importantly for ZnO-CuTCNQ NWs, no obvious degradation of current density was observed and the emission current fluctuation was less than 10% during a period of over 4000 seconds. It is of significance that the coating layer of ZnO NPs produced by our approach makes a great contribution to stabilization of organic field emitters and enhancement of their field emission properties. The high emission stability can be also observed for In2O3-CuTCNQ NWs which are fabricated by the same method. It is confirmed that the moderate approach presented herein is of practical significance in stabilization of organic field emitters avoiding decomposition of the core organic materials.