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.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
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)
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
perovskite type oxide
boron
photocatalytic activity
water
hydrogen
first principle calculation
