通过碱沉淀法制备了Ce,Al,Ni,Cu的水合氧化物,研究了它们的Langmuir吸附等温线,并利用BET法通过吸附-脱附氮气测定了其比表面积,同时对其吸附氟离子前后的变化进行了IR谱图的表征。结果表明不同水合金属氧化物具有不同的比表面积,其孔径分布也不尽相同,吸附量与比表面积之间没有直接相关的正比关系。吸附等温线均符合Langmuir吸附,表明单层吸附特征较明显。吸附前后IR研究表明,不同水合金属氧化物之间既有相同特征的吸附位,也存在不同特征的吸附位,这些吸附位的综合作用导致了不同水合金属氧化物之间氟离子吸附量的不同。
Hydrous oxides of cerium,aluminum,nickel and copper were prepared by alkaline precipitation method.Langmuir adsorption isotherm was studied and specific surface area was measured by BET method through N2 adsorption-desorption process.IR characterization of hydrous metal oxides before and after fluoride adsorption was also studied.Results show that different hydrous metal oxides have different specific surface areas and their pore size distributions also are not all the same.Adsorption capacity is not directly dependent on the specific surface area.Isotherm study indicates that the adsorption follows Langmuir model and shows the feature of monolayer adsorption.IR study before and after fluoride adsorption shows that different hydrous metal oxides have similar adsorption sites in the same IR region as well as adsorption sites in the different IR region.The comprehensive interaction of these adsorption sites with fluoride ions results in the different adsorption capacity of different hydrous metal oxides.