synthesis and characterization of nano-sized hexagonal and spherical nanoparticles of zinc oxide

zno plays an important role in many semiconductors technological aspects.  here,  direct  precipitation  method  was  employed  for  the synthesis of nano-sized hexagonal zno particles, which is based on chemical  reactions between  raw materials used  in  the  experiment. zno  nanoparticles  were  synthesized  by  calcinations  of  the  zno precursor precipitates  at 250  ˚c  for 3hours. the particle  size  and structure of the products have been confirmed by xrd. the ft-ir study  confirms  the  presence  of  functional  groups.  also,  the morphology  and  size  distribution  of  zno  nanoparticles  was analyzed by tem images. the optical properties were investigated by uv–visible  spectroscopy. the xrd  results  show  that  the  size of  the prepared nanoparticles  is  in  the  range  of 20–40 nm, which this value  is  in good agreement with  the tem  results. the ft-ir spectrum clearly indicates the formation of an interfacial chemical bond between zn and o. also  the uv absorption depends on  the particles  size  and morphology,  so  the  optical properties  enhances with  decreasing  nanoparticles  size.  moreover  the  direct precipitation technique is a feasible method for production of zno nanopowders.