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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 purple polycrystalline (NH_4) _5 [(VO) _6 (CO_3) _4 (OH) _9] · 10H_2O (I) was synthesized from V_2O_5, HCl, N_2H_4 · 2HCl and NH_4HCO_3 in 80% ~ 95% yield. TG / DTG and DTA thermal analysis of precursor I were carried out in N_2 gas stream.The effect of oxygen partial pressure (po_2) and reaction temperature on the product ratio of VO_2 was investigated when precursor I was pyrolyzed in N_2-air stream. The results showed that under the condition of 500 ℃, the value of x in VO_x was proportional to po_2. Under the condition of po_2 = 30.3 Pa, the product was hypoxia VO_2 in the range of 450 ~ 520 ℃. At t <450 ℃ and t> 520 ℃, the product is oxygen-enriched VO_2. Under different conditions, the VO_2 powder with different integral ratio from VO_ (1.927) to VO_ (2.080) was successfully synthesized.The composition of the product was uniform and the XRD spectrum was not observed Non-VO_2 impurity peak.VO_2 powder particles average particle size of 20nm, the particle size distribution and spherical.