Department of Physical and Theoretical Chemistry and Materials Chemistry, Al I Cuza University, Bd Carol I, No 11, 700506 Iasi, Romania.
J Hazard Mater. 2010 May 15;177(1-3):150-8. doi: 10.1016/j.jhazmat.2009.12.011. Epub 2009 Dec 6.
A new type of nanocomposite containing SnO(2) has been obtained by wet impregnation of dehydrated Mg/Al-hydrotalcite-type compounds with ethanolic solutions of SnCl(4).2H(2)O. Tin chloride hydrolysis was achieved using NaOH or NH(4)OH aqueous solutions, at pH around 9, followed by the conversion into corresponding hydroxides through calcinations. The powder X-ray diffraction (PXRD) and UV-Vis diffuse reflectance (UV-DR) methods confirmed the structure of as-synthesized solids. The chemical composition and morphology of the synthesized materials were investigated by energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The as-synthesized materials were used for photocatalytic studies showing a good activity for methylene blue decolourization, which varies with SnO(2) content and used as a hydrolysing agent. The proposed mechanism is based on the shifting of flat band potential of SnO(2) due to the interaction with Mg/Al-LDH, this being energetically favourable to the formation of hydroxyl radicals responsible for methylene blue degradation.
通过用 SnCl(4).2H(2)O 的乙醇溶液对脱水 Mg/Al-水滑石型化合物进行湿浸渍，得到了一种新型的含有 SnO(2)的纳米复合材料。在 pH 值约为 9 的条件下，使用 NaOH 或 NH(4)OH 水溶液实现了氯化锡的水解，然后通过煅烧转化为相应的氢氧化物。粉末 X 射线衍射（PXRD）和紫外-可见漫反射（UV-DR）方法证实了所合成固体的结构。通过能量色散 X 射线分析（EDX）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）研究了合成材料的化学组成和形态。所合成的材料用于光催化研究，显示出对亚甲基蓝脱色的良好活性，其活性随 SnO(2)含量和用作水解剂的不同而变化。所提出的机制基于 SnO(2)的平带电位由于与 Mg/Al-LDH 的相互作用而发生移动，这有利于形成负责亚甲基蓝降解的羟基自由基的形成，这在能量上是有利的。
