The Preparation Of Ultrafine Metal Cobalt And Its Compounds, And Nature Study

In this paper,superfine-cobalt was prepared by the method of liquid-phase reduction using hydrazine hydrate as reducer,CoSO₄·6H₂O,Co(NO₃)₂·6H₂O,(CH₃COO)₂Co·4H₂O as raw material in two solvent systems of water and alcohol.Studied the effects of the types of dispersant,the type of cobalt salt,reaction temperature,the order of the raw materials added to the product for the particle size and morphology.Analysis the structure and morphology of ultra-fine cobalt by XRD and SEM.The results show that ultra-fine cobalt powder are the six-party dense accumulation structure.In the water system,change the type of cobalt salts and the order of raw materials have been spherical,sea star,daisy-shaped,leaf-shaped ultra-fine particles of cobalt.In the alcohol system,changes the temperature and the types of solvent have been spherical,cauliflower-like,snow-like particles of cobalt.Using the same method of superfine-cobalt,the nano-diamond(ND) and nano boron carbide(B₄C) as the nuclei suspended in salt solution of cobalt,prepared the composites of ND/Co and B₄C/Co.XRD analysis showed that the ND/Co and B₄C/Co composites only diffraction peaks of the Co of hcp structure,did not show the ND and B₄C characteristic peaks. The sizes of ND/Co and B₄C/Co smaller than the pure Co.SEM analysis showed that the introduction of ND and B₄C made the particals from snowflake-like morphology into the irregular granular.Analysis the catalytic properties of the different size and different morphology of the ultra-fine Co and the ND/Co,B₄C/Co thermal decomposition for ammonium perchlorate(AP) by DSC.The results show that they are all have the catalysis for the thermal decomposition of AP;the smaller of particle size the better catalytic effect;a special morphology of the catalytic effect of cobalt powder is better than spherical catalytic effect of cobalt powder;the catalytic effect of complexes are superior to pure metal ultra-fine Co;the catalytic effect of B₄C/Co better than ND/Co.