介孔SO_4^(2-)/TiO_2的超声化学法合成表征及光催化性能  

SONOCHEMICAL SYNTHESIS & CHARACTERIZATION AND PHOTOCATALYTIC PERFORMANCE OF MESOPOROUS SO_4^(2-)/TiO_2

作　　者：金华峰[1] 李文戈[2] 

机构地区：[1]安康学院化学化工系,陕西安康725000 [2]上海工程技术大学材料工程学院,上海201600

出　　处：《硅酸盐学报》2009年第6期975-980,共6页Journal of The Chinese Ceramic Society

基　　金：陕西省教育厅自然科学专项基金(05JK135);上海市教委自然科学重点研究项目基金[(04)-03F202]资助项目。

摘　　要：以工业硫酸钛为原料,不使用有机模板剂,采用超声化学法一步水解制得吸附硫酸根的介孔偏钛酸,500℃焙烧得到介孔SO_4^(2-)/TiO_2固体超强酸催化剂。用X射线衍射、扫描电镜、高分辨透射电镜、Fourier变换红外光谱、低温氮吸附-脱附和紫外-可见光谱(ultraviolet-visible spectroscopy, UV-Vis)等多种手段对催化剂结构及光学性能进行了表征。结果表明:硫酸根在焙烧过程中与前驱体介孔偏钛酸孔壁上自由羟基的键合起到了孔结构导向及支撑作用。500℃焙烧后,样品具有161.3m^2/g的比表面积及4.1 nm的平均孔径,酸强度(H_0)介于-14.52与-16.02之间,硫的质量分数为2.8%,晶型全部为锐钛矿相。介孔SO_4^(2-)/TiO_2的UV-Vis吸收强于市售纳米TiO_2(Degussa P25),并使TiO_2的UV-Vis吸收光谱产生25 nm的红移,导致其光催化活性提高。以光催化降解对氯苯酚为探针反应,用250W紫外灯照射2h后,40mg/L的对氯苯酚降解率可达96.2%。Mesoporous metatitanic acid with plentiful SO4^2- absorbed was synthesized by an ultrasonic chemistry method and one-step hydrolysis method without organic templates. Mesoporous solid superacid catalyst SO4^2-/TiO2 was obtained by calcination at 500 ℃. The catalyst was characterized by an X-ray diffraction, transmission electron microscope, high-resolution transmission electron microscope, fourier transform infrared spectroscopy, N2 absorption/desorption, and ultraviolet-visible spectroscopy （UV-Vis）, and its photocatalytic activity was tested. SO4^2- bonded to free -OH on pore walls of metatitanic acid during the calcinations acts as the pore structure-directing agent and structure support. After calcinations at 500℃, the mesoporous SO4^2-/TiO2 which is in anatase phase has a specific surface area of 161.3 m2/g, an average pore diameter of 4.1 nm, sulfur mass fraction of 2.8% and acid strength （Ho） between -14.52 and -16.02 The UV-Vis adsorption spectrum show that the adsorption intensity of mesoporous SO4^2-/TiO2 is higher than commercially available TiO2 powders （Degussa P-25） and the sample has a red shift of the UV-Vis adsorption spectrum by 25 nm which causes its photocatalytic activity increased obviously. The photodegradation of p-chlorophenol was selected as a probe reaction to test the catalytic performance, after 2 h reaction under the ultraviolet-irradiation of 250 W, the degradation rate of p-hlorophenol is up to 96.2%.

关 键 词：介孔硫酸化二氧化钛 制备 表征 光催化 

分 类 号：TB321[一般工业技术—材料科学与工程] O643[理学—物理化学]