溶胶-凝胶法制备烧绿石型复合氧化物Sm_(2)InNbO_(7)及其光催化性能  

Preparation and photocatalysis property of pyrochlore-type Sm_(2)InNbO_(7) composite synthesized by sol-gel method

作　　者：陈龙[1] 叶红齐[1] 唐新德[1] 马晨霞[1] 周晚珠[1] 赵智[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2010年第5期463-468,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：高等学校博士学科点专项科研基金资助项目(200805330032)

摘　　要：以Nb2O5、In(NO3)3和Sm(NO3)3为原料,采用溶胶-凝胶法制备新型光催化材料Sm2InNbO7。采用X射线衍射(XRD)、扫描电镜(SEM)、比表面积分析(BET)以及紫外-可见漫反射光谱(UV-Vis diffuse reflectance spectroscopy)技术对该材料的结构、形貌和光吸收性能进行表征。以可见光下亚甲基蓝(MB)的脱色降解为模型反应,考察煅烧温度、催化剂用量、H2O2用量和pH值对Sm2InNbO7光催化性能的影响。结果表明,煅烧温度为700℃时即可获得具有烧绿石结构的Sm2InNbO7。随焙烧温度升高,催化剂结晶度增加,粒径增大,比表面积下降,吸收边界出现一定的蓝移;在850℃下煅烧3 h获得的Sm2InNbO7样品具有最高的催化活性,当50 mL质量浓度的10 mg/L的MB溶液中催化剂用量为0.1 g、30%H2O2溶液用量为0.5 mL、pH=6时,亚甲基蓝的降解率高达93.8%,明显优于固相法制备的Sm2InNbO7以及P-25 TiO2。较高的pH值有利于光催化反应的进行。Sm2InNbO7 powders were synthesized by sol-gel method using Nb2O5,In（NO3）3 and Sm（NO3）3 as raw materials.The structure,morphology and light absorbability of Sm2InNbO7 were characterized by XRD,SEM,BET and UV-Vis diffuse reflectance spectra,respectively.Taking the degradation of methylene blue（MB） dye under visible light irradiation（λ400 nm） as model reaction,the effects of calcination temperature,catalysts amount,H2O2 dosage and pH value of the solution on its photocatalytic property were studied.The results indicate that the pyrochlore-type Sm2InNbO7 composite can be synthesized by calcination at 700 ℃.The crystallization and grain size of Sm2InNbO7 increase,surface area decrease and absorption edge shows blue-shift with the increasing of calcination temperature.The optimum photocatalytic property of Sm2InNbO7 can be obtained when it calcined at 850 ℃ for 3 h by sol-gel method,which is much higher than those of Sm2InNbO7 and P-25 TiO2 synthesized by solid-state reaction method.The degradation rate of methylene blue can reach 93.8% at calcination temperature of 850 ℃,photocatalyst amount of 0.1 g,H2O2 dosage of 0.5mL and pH=6.The higher pH value is favorable for photocatalytic reaction.

关 键 词：溶胶-凝胶法 光催化 烧绿石结构 合成 

分 类 号：TQ426.62[化学工程]