Preparation of carbon-coated transition metal particles from mixtures of metal oxide and polyvinylchloride

摘要

Carbon-coated #alpha#-iron particles ca 100 mm in diameter were prepared through a simple heat-treatment of mixtures of Fe_3O_4 and polyvinylchloride (PVC) at 1000 deg C in an Ar flow. After HCl treatment of the particles to remove iron and iron compouds, hollow carbon particles were seen under the scanning electron microscope. According to thermogravimetric analysis of the Fe_3O_4-PVC mixture, the formation of carbon-coated #alpha#-iron particles proceeds in four steps with weioght loss,the first two steps being due to the hyrolysis and carbonization of PVC, and the last two to the reduction of Fe_3O_4 to #alpha#-Fe. Using the other transition metal oxide, NiO, CoO and Cu_2O, carbon-coated respective metal particles were also prepared using the same procedure.