La-TiO_(2)/高岭土对Cr(VI)的吸附-光催化协同净化性能  

Synergistic Effect of Adsorption-Photocatalytic Removal for Cr(VI)by La-TiO_(2)/kaolin Composites

作　　者：彭富昌 Peng Fuchang(College of Vanadium&Titanium,Panzhihua University,Panzhihua,Sichuan 617000;Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province,Panzhihua,Sichuan 617000)

机构地区：[1]攀枝花学院钒钛学院,四川攀枝花617000 [2]钒钛资源综合利用四川省重点实验室,四川攀枝花617000

出　　处：《非金属矿》2023年第6期97-100,104,共5页Non-Metallic Mines

基　　金：钒钛资源综合利用四川省重点实验室开放基金(2023FTSZ11);绿色催化四川省高校重点实验室开放基金(LYJ1906);四川省钒钛材料工程技术研究中心开放基金(2021-FTGC-YB-05)。

摘　　要：为改善TiO_(2)光催化材料对废水中重金属Cr(VI)的净化性能,以高岭土、硝酸镧和钛酸四丁酯为原料,采用溶胶-凝胶法制备了La-TiO_(2)/高岭土复合材料,通过X射线衍射(XRD)、扫描电镜/X射线能谱(SEM/EDS)和紫外-可见(UV-Vis)吸收光谱等手段表征了样品,研究了不同改性方法制得样品对Cr(VI)的吸附和可见光催化还原净化性能的影响。结果表明,La掺杂细化了TiO_(2)晶粒,稳定了TiO_(2)锐钛矿相结构,拓展其吸收光谱阈值,从而增强其光催化还原Cr(VI)的性能;高岭土复合改善了TiO_(2)的分散性,赋予样品大的比表面积,有利于对Cr(VI)的吸附,吸附过程符合Langmuir模型。掺杂和复合的耦合作用提高了TiO_(2)对Cr(VI)的吸附-可见光催化还原去除效率。La-TiO_(2)/高岭土在可见光辐照下6 h内对Cr(VI)的吸附-光催化净化效率最高达到96.5%,其光催化还原反应的表观一级动力学常数是纯TiO_(2)的2.6倍。To improve the purification performance of TiO_(2)photocatalytic materials for heavy metal Cr(VI)in waste water.La-TiO_(2)/kaolinite composites photocatalytic materials were prepared by sol-gel method with kaolin,lanthanum nitrate and tetrabutyl titanate as raw materials.The samples were characterized by XRD,SEM/EDS,and UV-Vis.The performance of adsorption and visible light photocatalytic reduction removal for Cr(VI)on samples prepared by different modification methods were studied.The results showed that La doping could refine TiO_(2)grains,stabilized phase structure of anatase TiO_(2),and expanded its absorption spectrum threshold,thereby enhancing its photocatalytic reduction activity of Cr(VI).Due to the composite of kaolin,the dispersion of TiO_(2)samples was improved and it was endowed with a large specific surface area,its adsorption ability for Cr(VI)was enhanced.The adsorption equilibrium process of TiO_(2)for Cr(VI)conformed to the Langmuir model.The coupling effect of doping and composite modification improved the adsorption and visible light catalytic reduction removal efficiency of Cr(VI)in composite material samples.The adsorption-photocatalytic purification efficiency of La-TiO_(2)/kaolinite for Cr(VI)under visible light irradiation for 6 hours reached the highest of 96.5%.The apparent first-order kinetic constant of its photocatalytic reduction reaction was 2.6 times that of pure TiO_(2).

关 键 词：La掺杂TiO_(2) 高岭土 复合材料 吸附-光催化 Cr(VI)净化 

分 类 号：O643.36[理学—物理化学] TQ034[理学—化学]