La掺杂TiO2的制备及光催化处理石化二级出水的研究  

Preparation of La-TiO2 and Photocatalytic Degradation of Petrochemical Secondary Effluent

作　　者：程振 王巍[1] 杨丽梅[1] 徐政[1] 纪仲光[1] 黄松涛[1] Cheng Zhen;Wang Wei;Yang Limei;Xu Zheng;Ji Zhongguang;Huang Songtao(National Engineering Laboratory of Biohydrometallurgy,General Research Institute for Nonferrous Metals,Beifing 100088,China)

机构地区：[1]北京有色金属研究总院生物冶金国家工程实验室

出　　处：《稀有金属》2018年第9期950-958,共9页Chinese Journal of Rare Metals

基　　金：北京市科委课题项目(Z151100003315016)资助

摘　　要：采用溶胶一凝胶法制备了稀土La掺杂TiO2纳米粉末，利用x射线衍射（XRD），紫外-可见漫反射光谱（UV—VisDRS）、透射电镜（TEM）和荧光光谱（PL）等分析方法对所制备样品进行表征；以亚甲基蓝和石化二级出水作为降解对象，研究了La掺杂TiO2样品的光催化性能。表征结果显示，本实验所制备的TiO2样品均为锐钛矿晶型；稀土La掺杂可以使样品的晶粒尺寸由25nm减小为15nm；同时可改善样品的团聚现象；并可促进样品对可见光的吸收；此外还具有降低电子一空穴的复合，提高TiO，量子效率的作用。光催化降解亚甲基蓝实验结果显示，当La掺杂含量为0．50％时，样品的光催化性能最佳；优选0．50％La—TiO2对石化二级出水进行光催化降解反应，结果显示光催化反应180min时，二级出水中的化学需氧量（COD）和UV254的降解率分别可达55％和70％以上；且经过3次回用后降解率未明显下降，说明本实验所制备的实验样品具有良好稳定的光催化性能，这为光催化深度降解石化二级出水工业应用提供了可能。TiO2 nanoparticles doped with the different concentrations of La were prepared by sol-gel method and characterized by X- ray diffraction （XRD）, ultraviolet-visible diffusion reflection spectroscopy （UV-Vis DRS） , transmission electron microscopy （TEM） and photoluminescenee （PL） spectra. The photoeatalytic activity of La-TiO2 nanopartieles was investigated by the degradation of meth- ylene blue and petrochemical secondary effluent. Characterization results showed that the prepared photoeatalysts were anatase phases. Compared with pure TiO2 , the doping of La could inhibit crystal growth, and improvethe dispersibility of La-TiO2 nanoparticles. The crystal size decreased from 25 to 15 nm. Besides, La dopingeould promote the absorption of visible light and lower the recombination rate of photo-generated electrons and holes, resulting in improvement of the quantum efficiency of TiO2. The photodegradation of meth- ylene blue results showed that the sample with 0.50% La had the best photoeatalytie performance and was used to study the photoeata- lytie degradation of petrochemical secondary effluent. The results showed that the degradation rates of the COD and UV254 were 55% and 70% , respectively, in petrochemical secondary effluent within 180 min. The degradation rate didn＇t decrease significantly after 3 times of cyclic utilization, indicating that the samples prepared had good photoeatalytie performance and stability. The study provided possibility for the photocatalytie degradation of petrochemical secondary effluent in industrial application.

关 键 词：TIO2 LA掺杂 光催化降解 石化二级出水 

分 类 号：O643[理学—物理化学]