A precursor of rod silver powders has been synthesized by coordination - precipitation process using ammonia as complex agent, AgNO3 and oxalate or ammonia oxalate as starting material. The phase, composition and morphology of the precursor were characterized by XRD and SEM analysis. The influences of various conditions in coordination - precipitation process, including the pH value , precipitation temperature , reactant concentration , ageing time on the morphology and size of the precursor particles were investigated. The results show that the precursor obtained in reaction system Ag( I ) - C2O42- -NH3 - NH4 + - H2O is oxalate silver, the morphology is rod and the optimum reaction conditions are 3. 8 ~ 4. 8 of pH value ,0.3 mol/L ~ 0.4 mol/L of silver ions concentration, 50 ~ 65℃ of coordination - precipitation temperature and 30 minutes of ageing time. The rod Ag particles with 1.054 m /g of specific surface area can be produced by thermal decomposition of the precursor in the inert atmosphere%以可溶性硝酸银和草酸或草酸铵为原料,利用氨为配位剂,通过配位沉淀法制备了棒状银粉前驱体,并采用X射线衍射仪和扫描电镜研究前驱体粉末的物相、成分与形貌,系统考察配位沉淀条件包括溶液pH值、反应温度、反应物浓度和陈化时间对前驱体粉末形貌、粒度和成分的影响.结果表明:Ag(Ⅰ)-C2O42--NH3-NH4+-H2O反应体系中,在溶液pH =3.8 ～4.8,温度50～65℃,浓度0.3～0.4 mol/L,陈化时间为30 min的条件下可得到草酸银前驱体,其形貌为棒状.在惰性气氛下热分解该前驱体即可得到比表面积为1.054 m2/g棒状银粉,热分解产物对前驱体的形貌具有继承性.
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