不同整比性VO_2纳米粉体的合成  

Synthesis of Various Stoichiometry Nano-powder of VO_2

作　　者：何山[1] 林晨[2] 雷德铭[1] 郑臣谋[2] 

机构地区：[1]中山大学物理系,广州510275 [2]中山大学化学系,广州510275

出　　处：《高等学校化学学报》2003年第5期761-764,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:59972045);广州市科技局基金(批准号:2002J1-C0371)

摘　　要：以V_2O_5,HCl,N_2H_4·2HCl和NH_4HCO_3为原料合成了紫红色多晶(NH_4)_5[(VO)_6(CO_3)_4(OH)_9]·10H_2O(I),产率80％～95％.在N_2气流中对前体I进行了TG/DTG和DTA热分析.研究了前体I在N_2-空气气流中热解时氧分压(po_2)和反应温度对产物VO_2整比性的影响。结果表明,在500℃条件下,VO_x中的x值与po_2呈正比关系,在po_2=30.3 Pa条件下,在450～520℃区间,产物为缺氧VO_2;在t<450℃和t>520℃时,产物为富氧VO_2.在合适的条件下,成功地合成了从VO_(1.927)到VO_(2.080)之间不同整比性的VO_2粉体.产物组成均匀,其XRD谱未观察到非VO_2的杂质峰.VO_2粉体颗粒的平均粒径为20nm,粒度分布均匀并呈球形。The violet polycrystalline (NH4)5 [(VO)6(CO2)4(OH)9] ·10H2O( Ⅰ ) was synthesized by using V2O5, HC1, N2H4 ?2HC1 and NH4HCO3 as the starting materials. The yield was 80 %- 95%. The TG/DTG and DTA of I were studied in a flow of N2. The effects of partial pressure of oxygen(po2) in N2-air flow and temperature of reaction on VO2 stoichiometry were investigated in the pyrolysis of Ⅰ in a silica tube. The results show that x value of VOx is proportional to po2 at pyrolysis temperature of 500 ℃ At po2 = 30. 3 Pa and in the temperature range from 450 to 520 ℃ the products are oxygen-deficient VO2, and when the temperature is lower than 450 ℃ or higher than 520 ℃ the products are oxygen-rich VO2. In this paper, various stoichiometry VO2 powders from VO1.927 to VO2.080 were successfully synthesized by pyrolysizing the precursor. XRD patterns of VO2 show that none of the impurity peaks was observed. The SEM micrograph of sample indicates that as-prepared VO2 is spherical particles with mean size 20 nm and is homogeneous in distribution. Further experiments testify that the composition of nano-powders is homogeneous.

关 键 词：二氧化钒 纳米粉体 整比性 合成 半导体 

分 类 号：TN304.21[电子电信—物理电子学] TB383[一般工业技术—材料科学与工程]