几种赤铁矿的制备、表征及其对氟的吸附性能研究  

Preparation,characterization and fluoride adsorption characteristics of three hematite samples

作　　者：向文军[1] 朱朝菊[1] 魏世勇 XIANG Wenjun;ZHU Zhaoju;WEI Shiyong(School of Chemistry and Chemical Engineering,Sichuan University of Arts and Science,Dazhou 635000,China;Department of Chemistry and Environmental Engineering,Hubei University for Nationalities,Enshi 445000,China)

机构地区：[1]四川文理学院化学化工学院,四川达州635000 [2]湖北民族学院化学与环境工程学院,湖北恩施445000

出　　处：《化学研究与应用》2018年第2期290-296,共7页Chemical Research and Application

基　　金：国家自然科学基金项目(41561053;41261060)资助;四川省教育厅科研项目(15ZA0317)资助;达州市科技局应用基础研究项目(KJJ201403)资助

摘　　要：采用水热合成法、灼烧针铁矿和纤铁矿的方法制备了3种赤铁矿,分别记为Hem-1、Hem-2和Hem-3;用X-射线衍射(XRD)、扫描电镜(SEM)、比表面及微孔分析、质子电位滴定等技术分析了样品的表面性质,并研究了样品吸附氟离子的特性。结果显示,Hem-1为纯度高、结晶度良好的赤铁矿,Hem-2和Hem-3为结晶度依次减弱的赤铁矿。Hem-1、Hem-2和Hem-3分别为100~200 nm的似球状物、长度200~500 nm的棒状物和100 nm左右无特征形貌的纳米颗粒。Hem-1、Hem-2和Hem-3的比表面积分别为24.46、23.29和37.16 m2·g^(-1)。样品的表面分形度和表面活性羟基密度都表现为Hem-1<Hem-2<Hem-3。Hem-1、Hem-2和Hem-3对氟离子的最大吸附量qmax分别为6.23、7.19和10.54 mg·g-1。可见,不同方法制备的赤铁矿对氟的吸附容量有较大差异。Langmuir模型比较适合拟合Hem-1和Hem-2对氟离子的等温吸附数据(R2分别为0.988和0.991),而Freundlich模型对Hem-3的等温吸附数据的拟合度较高(R2为0.971)。这表明Hem-1和Hem-2对氟离子的吸附为匀质性表面的单层吸附,而异质性表面的多层吸附为Hem-3吸附氟离子的主要模式。Three hematite samples were respectively prepared through hydrothermal synthesis and burning goethite and lepidocro-cite,and the samples were denoted as Hem-1,Hem-2and Hem-3,respectively.The surface properties of the samples were investiga-ted using X-ray diffraction(XRD),scanning electron microscope(SEM),specific surface and pore analysis and proton potentiomet-ric titrations.The adsorption characteristics of fluoride by the samples were also studied.Results showed that Hem-1possessed a good crystallinity and high purity,the crystallinity of Hem-2and Hem-3decreased successively.The micrographs of Hem-1and Hem-2particles were approximately spherical shape with a diameter of100-200nm and needle-shaped particles with a length of200-500nm,respectively.The particles of Hem-3had no distinctive micrograph with a particle size of ca.100nm.The specific surface area of Hem-1,Hem-2and Hem-3was24.46,23.29and37.16m2?g1,respectively.Both the surface fractal degree and active hydroxyl density of the samples followed the order of Hem-1<Hem-2<Hem-3.The maximum adsorption capacity(qmax)of Hem-1,Hem-2and Hem-3was6.23,7.19,and10.54mgug1,respectively.It could be seen that the adsorption capacities of hem-atite from different methods were significantly different.Langmuir model was suitable to describe the isotherm adsorption data of Hem-1and Hem-2(R2=0.988and0.991),while the correlation coefficient of Freundlich model for the isotherm adsorption data of Hem-3was relatively high(R2=0.971).This indicated that the adsorption mode for fluoride onto Hem-1and Hem-2was the mono-layer adsorption of the homogeneity surface,and the multi-layer adsorption of the heterogeneity surface was important in adsorbing fluoride onto Hem-3

关 键 词：赤铁矿 制备方法 表面性质 吸附 氟 

分 类 号：O614.81[理学—无机化学]