Characterization of Carbon-Coated ZnO Composite Powders Produced by Polymer Pyrolysis Method

Abstract

In this study, carbon-coated ZnO powders were prepared via polymer pyrolysis method, polymer being used as poly (vinyl alcohol) and poly (vinyl chloride). Initial conditions, Type of polymer as carbon sources and particle-particle distance during the coating operation, were located as important parameters which directly affect the high quality of carbon-coated ZnO powders. After coating, morphologies and crystal structure of the carbon-coated samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and specific surface area measurement (BET). From BET data, the increase in specific surface area was observed after coating, irrespective of carbon source. The reason why the specific surface area increased after coating was based on nanoporous formation in the carbon film coated on the surface of powder. By TEM observation, it was found that nano-structure of carbon prepared from poly (vinyl alcohol) was different from that obtained from poly (vinyl chloride).