Fe~(3+)、Eu~(3+)共掺纳米TiO_2光催化降解N-(2-苯并咪唑基)-氨基甲酸甲酯

采用溶胶-凝胶-微波法制备Fe3+、Eu3+共掺杂纳米TiO2(Fe/Eu-TiO2),并通过紫外-可见吸收光谱(UV-Vis)、荧光光谱(FS)、X射线衍射(XRD)、扫描电镜(SEM)、比表面积测定(BET)等手段对其进行表征。结果表明:在500℃氮气保护下退火制得的Fe/Eu-TiO2为锐钛矿相纳米颗粒,平均粒径为20—50 nm;对可见光的响应范围为370—770 nm。光催化降解N-(2-苯并咪唑基)-氨基甲酸甲酯(多菌灵)的实验表明,Fe3+、Eu3+共掺杂对TiO2光催化表现出协同增效作用,在可见光下能产生更多的羟基自由基,对多菌灵降解速率常数kapp为0.046 66 min-1,大于分别单掺Fe3+和Eu3+的TiO2纳米粒子。

Preparation of TiO2 nanoparticles co-doped with Fe3+ and Eu3 + and photocatalytic degradation of carbendazim

Nanoparticles of TiO2 co-doped with Fe3+ and Eu3+ were prepared in anhydrous ethanol media by sol-gel-microwave method.Fe/Eu-TiO2 photocatalysts were prepared by modification of TiO2 fine particles of anatase structure through heating in N2 at 500 ℃.The as-prepared photocatalysts were characterized by UV-Vis,FS,XRD,SEM and BET.The photodegradation of carbendazim was used as probe reaction to examine their photoactivity and analyze the apparent kinetic constants.The results show that Fe3+ and Eu3+ co-doped TiO2 whose crystalline size is in the range of 20-50 nm extends the absorption spectra into the visible region over the range 370-770 nm,thus presenting the best photocatalytic activity under UV and visible light.Meanwhile,the photocatalytic degradation rate constant kapp(0.046 66 min-1) of Fe/Eu-TiO2 is higher than that of Fe3+ or Eu3+ single-doped TiO2.The kinetics and mechanism of the reaction indicates that the Eu3+ and Fe3+ co-doping promotes the photocatalysis by capturing the photogenerated electrons and may induce the formation of HO·.