Ang Wei

Field Emission From Hydrothermally Grown ZnO Nanoinjectors

An injector-like nanostructure of ZnO fabricated by hydrothermal method was tested for field emission (FE) properties. The turn-on field of 3.8 V/mum was obtained at a current density of 0.1 muA/cm2. Above the turn-on field, the emission current density quickly raised up to 1 mA/cm2 at about 12.8 V/mum. The field enhancement factor beta was estimated to be 2556 and 1226 in the low and high field regions, respectively. The two-slope FE behavior was attributed to the adsorbates and defects which were introduced in the fabrication process in aqueous solution at low temperature. The good FE properties of the ZnO nanoinjectors indicate that they are applicable as low-cost and low-temperature cathode materials for FE-based devices.

Methyl-viologen modified ZnO nanotubes for use in electrochromic devices

Efficiently changing optical properties (reflectance, transmittance, and absorbance) through reversible color changes of electrochromic (EC) materials is challenging and critical in achieving high-performance EC devices. In this work, we have prepared methyl-viologen modified ZnO nanotubes (NTs) as an electrode material, which exhibits good durability, a high transmittance modulation range (70%) and fast response times (6 s and 3 s for coloration and bleaching respectively). The results indicate the potential application of ZnO NTs in smart windows, optical displays, electronic papers and so on.

Fabrication of an Ag/Fe2O3/ZnO ternary composite with enhanced photocatalytic performance

A novel Ag/Fe2O3/ZnO ternary composite was fabricated using the chemical deposition and photochemical deposition methods. Its structure and optical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet-visible spectrophotometry. The Ag/Fe2O3/ZnO ternary composite exhibited a greater improvement in photocatalytic activity compared with the Fe2O3/ZnO or Ag/ZnO binary composite. The degradation rate of Ag/Fe2O3/ZnO towards methyl orange (MO) and iodoform (CHI3) within 120 min was 80% and 94%, respectively. More importantly, the Ag/Fe2O3/ZnO composite had a much higher degradation efficiency towards iodoform, which indicates its efficient and selective degradation characteristics. The results show that the Ag/Fe2O3/ZnO ternary composite holds great potential in the removal of carcinogenic iodoform from sewage.