TiO2 光催化交流贴 (2) --- 颗粒尺寸和结晶度对催化性能的影响？长久以来，大家都认识到结晶度和晶粒尺寸对TiO2的光催化性能有很大的影响。但是由于制备条件的限制，很难同时控制TiO2样品的结晶度和晶粒尺寸，严重影响了我们深入了解二者对光催化性能和反应过程的理解，从而无法更好的设计新型的 催化剂 。在这篇文章中，我们首先利用超临界合成方法制备了两个系列的纯anatase。其中C系样品只改变结晶度而具有相同的晶粒尺寸，S系样品只改变晶粒尺寸而具有相同的结晶度。在此基础上，我们深入研究了结晶度和晶粒尺寸对光催化降解 苯酚 的影响。实验结果表明，结晶度对光催化降解苯酚基本没有影响，而晶粒较大的anatase活性比小晶粒anatase要好。我们接下来深入分析了光催化降解苯酚的动力学参数，惊奇的发现晶粒对苯酚降解的过程影响非常大，预知详情，请看全文。。。? ?（不好意思，打字实在太累了）AbstractCrystallite size and crystallinity have been recognized as important parameters that influence the photocatalytic performance of pristine TiO2 nanoparticles. But how these two parameters individually affect the photo-reactivity of TiO2 remains unclear and debated due to the difficulties in preparing well-controlled TiO2 photocatalysts that vary crystallite size and crystallinity independently. Here, we have studied the effect of crystallite size and crystallinity on phenol photo-decomposition using well-defined anatase nanoparticles synthesized under supercritical water–isopropanol conditions. The photo-reactivity was found to increase with increasing crystallite size but to be independent of the crystallinity. By tracking the evolution of phenolic intermediates, we explored the reaction kinetics and demonstrated that an increase in the crystallite size of anatase nanoparticles can significantly suppress undesired hydroquinone–benzoquinone redox reactions and thus promote the full decomposition of phenol and phenolic compounds.全文链接： http://www.sciencedirect.com/sci ... i/S0021951713001589toc_rs.jpg查看更多4个回答 . 15人已关注
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