原位铬掺杂氧化铝纳米棒的水热合成（英文）

In-situ Cr-doped Alumina Nanorods Powder Prepared by Hydrothermal Method

以Al(NO_3)_3·9H_2O、Cr(NO_3)_3·9H_2O和尿素为原料,PEG-20000为表面活性剂,采用水热法合成了铬掺杂碳酸铝铵纳米棒,经1200℃煅烧后,成功制备原位铬掺杂氧化铝纳米棒。利用XRD、SEM和FTIR对产物晶相组成、结构和形貌进行了表征,采用UV-Vis光谱和全自动测色色差计对产物的呈色性能进行测试。结果表明:铬掺杂碳酸铝铵纳米棒经1200℃煅烧后,实现了铬在氧化铝基体中的原位掺杂,两者形成了完全固溶体,固溶体晶体结构为刚玉型。随着铬掺杂量的增加,所制备的碳酸铝铵纳米棒长度变短,煅烧后的产物出现熔融现象。样品的紫外可见吸收光谱结果表明,制备的铬掺杂氧化铝基纳米粉体分别在372,406,562 nm存在较强的吸收峰,因而样品会呈现淡红色,这与全自动测色色差计测得的色度值相一致。利用水热合成原位铬掺杂氧化铝纳米棒提高了铬与氧化铝的混合均匀度,在较低温度下生成了刚玉相,有助于刚玉型耐火材料、刚玉磨料和铬铝红颜料的制备与应用。

Cr-doped ammonium aluminum carbonate hydroxide nanorods were prepared by a hydrothermal method,with Al（NO_3）_3·9H_2O,Cr（NO_3）_3·9H_2O,and urea as raw materials and PEG-20000 as surfactant.In-situ Cr-doped alumina nanorods powder was obtained through calcining its precursors（Cr-doped ammonium carbonate hydroxide nanorods） at 1200 ℃.The crystal composition,the structure and the morphology of the as-prepared products were characterized by XRD,SEM and FTIR.Besides,the color performances of the products were analyzed by UV/Vis/NIR spectrometer and automatic color measurement.Results show that the precursors of Cr-doped alumina nanorods powder prepared by the hydrothermal method are composed of uniform nanorods.After its calcinations at 1200 ℃,the in-situ doping of Cr in the alumina substrate is achieved.In the Cr-doped alumina nanorods powder,a continuous solid solution of Cr_2O_3 and Al_2O_3 is formed,which has a corundum crystal structure.With the increasing Cr content,Cr-doped ammonium aluminum carbonate hydroxide nanorods gradually become short,and the melting phenomenon occurs in calcined products.UV-Vis spectroscopy analysis shows that Cr-doped alumina nanorods powder has three strong absorption bands at 562,406 and 372 nm,thus leading to a pink color for samples which is in agreement with chromatic data.In the present study,Cr-doped alumina nanorods powder prepared by the hydrothermal method can reduce the formation temperature of corundum crystal structures and resolve the problem of mixing homogeneity of Al_2O_3 and Cr_2O_3,which will contribute to the preparation and the application of alumina-chrome refractory,pink corundum abrasive and ceramic pigment.