Department of Chemistry, Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Normal University, Shanghai, 200234, China.
Nanoscale. 2012 Jan 21;4(2):455-60. doi: 10.1039/c1nr11331c. Epub 2011 Nov 17.
A new hierarchical visible-light-driven photocatalyst Bi(2)TiO(4)F(2) was synthesized by a solvothermal method for the first time. The photocatalyst was characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N(2) adsorption-desorption (BET), UV-vis diffuse reflectance spectroscopy (DRS). Such hierarchical Bi(2)TiO(4)F(2) microspheres assembled by nanosheets were fabricated via an Ostwald ripening process in the absence of soft templates (surfactants). The as-prepared samples' bimodal pore-size distributions in the mesoporous region consisted of smaller intra-aggregated pores with peak pore diameter of ca. 4.6 nm and larger inter-aggregated pores with peak pore diameter of ca. 17.0 nm. The band gap of the obtained Bi(2)TiO(4)F(2) was estimated to be about 2.71-3.06 eV for various solvothermal treatment time. Owing to the hierarchical structure with bimodal pores, low band gaps and high crystallinity, the Bi(2)TiO(4)F(2) microspheres exhibited high photocatalytic performance and durability for the degradation of rhodamine B (RhB) under visible light (> 420 nm). It was proved that the photo-generated holes and ˙OH radicals played an essential role for the oxidation of RhB.
一种新型的可见光驱动光催化剂 Bi(2)TiO(4)F(2) 首次通过溶剂热法合成。通过 X 射线粉末衍射 (XRD)、场发射扫描电子显微镜 (FESEM)、透射电子显微镜 (TEM)、N(2)吸附-解吸 (BET)、紫外可见漫反射光谱 (DRS) 对光催化剂进行了表征。这种由纳米片组装而成的分级 Bi(2)TiO(4)F(2) 微球是通过在没有软模板（表面活性剂）的情况下的奥斯特瓦尔德熟化过程制备的。所制备样品的介孔区域中的双峰孔径分布由具有约 4.6nm 峰值孔径的较小内聚孔和具有约 17.0nm 峰值孔径的较大聚孔组成。获得的 Bi(2)TiO(4)F(2) 的带隙约为 2.71-3.06eV，这取决于不同的溶剂热处理时间。由于具有双峰孔、低带隙和高结晶度的分级结构，Bi(2)TiO(4)F(2) 微球在可见光（>420nm）下表现出高的光催化性能和对罗丹明 B（RhB）的降解耐久性。证明了光生空穴和˙OH 自由基在 RhB 的氧化中起着重要作用。
