摘要
采用喷雾干燥法制备中空偏钨酸铵球,通过调整热处理温度制备空心介孔WO3球。结果表明：具有Keggin结构的[H2W12O40]6-金属簇的破坏温度区间为417~439℃;在热处理温度为500、550℃,仍有少量的铵根和结合水没有分解,除了WO3外,还存在（NH4）0.06WO3（H2O）0.11;当热处理温度在600℃以上时,偏钨酸铵完全分解为WO3;热处理温度为700℃,保温时间为2h,得到空心介孔WO3球。其形成机理为：空心的偏钨酸铵球,在热处理过程中由于各亚晶的位向不一致,各亚晶沿着[002]晶向择优生长,亚晶形成狭长颗粒,从而在空心球表面形成了介孔;但当热处理温度为800℃,保温时间为2 h,晶粒与晶粒之间通过合并而长大,孔道也随之消失;空心介孔WO3球具有良好的光催化效果,500 W高压汞灯照射150 min甲基蓝的降解率为65.9%。
Based on the hollow ammonium metatungstate spheres（HAMTS） prepared by spray drying method,hollow mesoporous WO3 spheres were synthesized by adjusting calcination temperature.The results show that [H2W12O40]6-with Keggin structure in HAMTS is destroyed in the temperature of 417 to 439 ℃.Apart from WO3,a small amount of ammonium ions and bounding water still exist in the form of（NH4）0.06WO3（H2O）0.11 in the sample after being calcined at 500 or 550 ℃.Increasing temperature to 700 ℃ for 2 h,hollow mesoporous WO3 spheres can be obtained.The mechanism for the formation of hollow mesoporous structure is proposed as follows.Due to the difference of the subgrain orientation and the preferred growth,narrow particles are crystallized by integrating HAMTS subgrains during the heat treatment process,leading to the mesoporous structure on the surface of hollow WO3 spheres.When the sample is calcined at 800 ℃ for 2 h,the channels between the grains disappear.The photocatalytic degradation rate of methylene over blue hollow mesoporous WO3 spheres is 65.9% under the illumination of 500 W high pressure mercury arc for 150 min.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2012年第3期465-470,共6页
Chinese Journal of Inorganic Chemistry
基金
北京创新人才项目(No.PHR201006101)
北京教委基金(No.KZ2010100050001
No.KM201110005003)
国家自然科学基金(No.51002004)
研究生科技创新基金(No.YKJ-2011-6000)资助项目
关键词
介孔
空心
WO3
光催化
mesoporous
hollow
WO3
photocatalysis
