ZnO Nanostructures: Hydrothermal Synthesis and Characterization


Eşgin H. , Çağlar Y.

Internatinonal Conference on Materials Science, Mechanical and Automotive Engineerings and Technology, İzmir, Turkey, 10 - 12 April 2018, pp.651

  • Publication Type: Conference Paper / Summary Text
  • City: İzmir
  • Country: Turkey
  • Page Numbers: pp.651

Abstract

Zinc Oxide (ZnO) nanostructures have been used as photoelectrode materials in semiconductor photovoltaic cells which can convert solar energy directly into electrical energy. In this study, ZnO nanostructures, which are thought to be used in dye-sensitized solar cells, have been deposited by hydrothermal syhthesis method. Some structural, morphological and optical properties of the synthesized ZnO nanostructures have been investigated. These nanostructures have been produced with hydrothermal synthesis method using zinc nitrate (Zn(NO3)2.6H2O) initial salt. Sodium dodecyl sulfate (NaC12H25SO4; SDS) and polyvinylpyrrolidone ((C6H9NO)n; PVP) were used as surface active materials, respectively. Sodium hydroxide (NaOH) was used as a reactant during production. The effects of changes in SDS, PVP and NaOH quantities on the morphological and structural properties of ZnO nanostructures have been investigated and their use in dye-sensitized solar cells has been discussed. The Scanning Electron Microscopy (SEM) was used to determine the morphological properties of the synthesized ZnO nanostructures. It has been observed that the size of the nanostructures formed by the increase of the amount of NaOH used at the synthesis, when no reactant is used, is increased. Synthesis using SDS or PVP generally has a leaf-like structure. The increase in the amount of surfactant material causes the ZnO nanostructures to become porous, whereas the decrease causes the nanostructures to grow adjacent to each other. To investigate the crystalline structure and the orientation of the ZnO nanostructures, XRD patterns were used. The lattice parameters and texture coefficient values of these nanostructures were determined. The band gap of ZnO nanoflakes were investigated from absorbance curves obtained by a spectrophotometer. The obtained ZnO nanostructures are expected to have high surface areas due to their nanostructure and leaf-like properties, and therefore it is predicted to play an important role in obtaining  high efficiency in photovoltaic applications.