纳米BiOI的稳定性、结构及光催化性能研究
来源期刊：有色金属科学与工程2011年第4期
论文作者：余长林 操芳芳 李鑫 杨凯
文章页码：86 - 91
关键词：Bi-基光催化剂；热处理；微结构；禁带宽度；光催化活性
Key words：Bi-based photocatalyst; thermal treatment; micro-structure; band gap energy; photocatalytic activity
摘 要：首先在水溶液中通过沉淀反应制备了BiOI，然后在不同温度下对其进行焙烧，考察其稳定性对不同温度焙烧制得的样品进行了X-射线粉末衍射(XRD)、热重(TGA)、扫描电镜(SEM)、透射电镜(TEM)、紫外可见(UV-vis)漫反射(DRS)吸收等表征以可见光(λ>420 nm)为光源，对在不同温度焙烧后的样品进行了光催化降解亚甲基蓝模拟废水的活性测试结果表明，BiOI不是一种稳定的化合物它在焙烧过程中可以发生由BiOI→Bi5O7I→α→Bi2O3的系列化学变化紫外可见漫反射测试和计算结果表明，BOI、Bi5O7I、Bi5O7I/Bi2O3混合物和Bi2O3各样品对应的禁带宽度分别为1.80 eV、2.47 eV、2.77 eV和3.15 eV在可见光照射下，光催化活性顺序为BiOI> Bi5O7I>Bi5O7I/Bi2O3混合物>Bi2O3这与催化剂对可见光的吸收能力变化相一致.
Abstract: Bismuth oxyiodide plates were prepared by a solution-based method and then calcined at various temperatures. The as-prepared samples were characterized with X-ray diffraction (XRD), thermogravimetry (TCA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectra (DRS), respectively. The photocatalytic activity of the samples was evaluated by photocatalytic decolorization of a methylene blue under visible light (λ>420 nm) irradiation. Results show that BiOI is not a thermally stable compound. It undergoes a series of transformation BiOI→Bi5O7I→αBi2O3 during thermal treatment. The band gaps of the as-prepared samples were found to be l.80, 2.47, 2.77, and 3.15 eV for BiOI, Bi5O7I, Bi5O7I/Bi2O3 mixture, and Bi2O3, respectively. Under visible light irradiation, the photocatalytic activity follows the order: BiOI>Bi5O7I>Bi5O7I/Bi2O3 mixture> Bi2O3. This corresponds to the absorption ability of the catalysts to visible light.
