硼掺杂对K_2La_2Ti_3O_(10)光催化分解水制氢活性的影响  

Photocatalytic Activity of K_2La_2Ti_3O_(10) Doped with Boron for Hydrogen Production from Water Splitting

作　　者：杨亚辉[1,2] 陈启元[1] 李洁[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]中南大学资源加工与生物工程学院,湖南长沙410083

出　　处：《催化学报》2009年第2期147-153,共7页

基　　金：国家高技术研究发展计划(863计划;2002AA327140);湖南省自然科学基金(08JJ3022);湖南省科技计划(08FJ4105)

摘　　要：通过溶胶-凝胶法制备了层状钙钛矿复合氧化物K2La2Ti3O10及B掺杂的K2La2Ti3O10,并采用X射线衍射和紫外-可见漫反射光谱等对制得样品进行了表征.以I-为电子给体,分别在紫外和可见光辐射下研究了所制得样品光催化分解水的产氢活性;采用第一性原理,计算了B掺杂对K2La2Ti3O10半导体能带结构和态密度的影响,从电子结构的变化揭示了掺杂引起光催化活性差异的原因.结果表明,B的掺入能够提高K2La2Ti3O10的光解水产氢活性且存在合适的B掺杂浓度.当B与Ti的摩尔比为0.01∶1时,紫外光催化分解水产氢速率为151.7μmol/(L.h),比未掺杂B的K2La2Ti3O10产氢速率提高166%;当B与Ti的摩尔比为0.02∶1时,可见光催化分解水产氢速率为85.2μmol/(L.h),为未掺杂B的K2La2Ti3O10产氢速率的5.2倍.The layered perovskite type oxides, K2La2Ti3O10 and K2La2Ti3O10 doped with B, were prepared by the sol-gel method and characterized by power X-ray diffraction and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of K2La2Ti3O10 and K2La2Ti3O10 doped with B for water splitting was investigated with I^- as the electron donor under ultraviolet and visible light irradiation. The electronic structure of K2La2Ti3O10 doped with B was analyzed by the first principle calculations, which reveals the photo responses in the visible region and the improvement of the photocatalytic activity of K2La2Ti3O10. Conclusions were made that K2La2Ti3O10 doped with B exhibited higher photocatalytic activity for hydrogen production. The optimum doping concentration of B was 0.01：1 （B： Ti）, and the ultraviolet hydrogen production rate was 151.7 μmol/（L· h）, which was raised by 166% compared with undoped K2La2Ti3O10. The optimum doping concentration of B was 0.02：1 （B：Ti）, and the visible hydrogen production rate was 85.2 μmol/（L·h）, being 5.2 times that undoped K2La2Ti3O10.

关 键 词：钙钛矿复合氧化物 硼 光催化活性 水 氢气 第一性原理 

分 类 号：TQ116.2[化学工程—无机化工]