溶胶-凝胶法低温制备氧化钒晶体(英文)

Low Temperature Synthesis of Vanadium Pentoxide Nanocrystallines by Sol-Gel Method

采用溶胶-凝胶法在大水体系下制备了V_2O5纳米晶体。利用X射线衍射仪(XRD)和透射电镜(TEM)时样品的结构与形貌进行了分析。结果表明:当pH<3时,随着pH值减小,产物的结晶度越高,晶粒尺寸越大;当人(水:丙酮酸钒摩尔比)大于200时,W越大,产物结晶度越高,晶粒尺寸越大。当pH≤1和W≥200时,在低温50℃下,通过溶胶-凝胶法制备了V_2O_5·1.6H_2O晶体,在400℃热处理后得到了较纯的V2O5晶体,该晶粒平均尺寸约为8 nm。

V_2O_5 nanocrystalline was prepared by sol-gel method in a system with large amount of water.The structure and morphology of the as-prepared samples were characterized by XRD and TEM.The results show when the pH was ≤3,the crystallinity and crystal size of the as-prepared samples increased with decreasing pH.When the molar ratio of water to vanadium oxyacetyl acetonate(W) was more than 200,the crystal size of the as-prepared sample increased with increasing W.When W was≥200,and pH was ≤1,V_2O_5·1.6H_2O nanocrystallines were obtained at a low temperature of 50 ℃.Post-heat-treatment caused the decrease of crystal intensity of V_2O_5 1.6H_2O,and increase of crystal intensity of V_2O_5.After post-heat-treat at 400 ℃,pure V_2O_5was obtained.The average size of V_2O_5 nanocrystalline was about 8 nm at 400 ℃.