【摘要】 将V2O5溶解于有机酸溶液中,通过喷雾干燥制得非晶态含钒的粉末前驱体,将前驱体粉末还原/碳化后得到V8C7粉末。采用X射线衍射仪、扫描电镜、透射电镜、碳氧分析仪对工艺过程产品进行分析。结果表明:前驱体是粒度为10~20μm非晶态球形粉末,当温度升高到400℃时,前驱体粉末开始分解;当温度升高到600℃时,前驱体粉末全部转变为V2O3与游离C原子级别混合均匀的复合粉末;随着温度的升高,游离C还原碳化V2O3,当温度升高到800℃时,出现V4C3相;在约1 100℃时,得到相成分均一的V8C7粉末,其形貌是粒径为30~50 nm的一次颗粒形成的多孔空壳球形,其总C含量为17.38%,游离C含量为0.47%。前驱体粉末在加热过程中相成分转变过程为:V2O3→V4C3→V8C7,不经历V2O3转变为VO的过程。更多还原

【Abstract】 Dissolving V₂O₅ in organic acid solution,the amorphous powder precursor which contained vanadium was obtained by spray drying,and the nanometer V₈C₇ powder was prepared through reduction/carbonization of the precursor powder.The technological process was investigated and analyzed using X-ray diffractometer,scanning electron microscope（SEM）,transmission electron microscope（TEM） and carbon & oxygen analyzer.The results show that the precursor is（amorphous） spherical powder of 1020μm.When the temperature rises to 400℃ in vacuum,the precursor begins to decompose;when the temperature rises to 600℃,all the precursor powder is transformed into the composite powder in which V₂O₃ mixes with free carbon homogeneously atom-level;V₂O₃ is reduced and carbonized by free carbon with the temperature,and when the temperature goes up to 800℃,the V₄C₃ phase occurs.At about 1100℃,the V₈C₇ powder is obtained with single phase,and its morphology is of porous hollow sphere formed by many first particles of 3050nm.The total carbon content is 17.38% and the free carbon content is 0.47%.In the process of reduction/carbonization,the precusor powders undergo the following phase transformation: V₂O₃→V₄C₃→V₈C₇,without undergoing the process of phase transformation from V₂O₃ into VO phase.更多还原