One-step construction of Pickering emulsion via commercial TiO2 nanoparticles for photocatalytic dye degradation
One-step construction of Pickering emulsion via commercial TiO2 nanoparticles for photocatalytic dye degradation
复制标题
通过商业 TiO2 纳米颗粒一步构建 Pickering 乳液用于光催化染料降解
DOI：
10.1016/j.apcatb.2019.02.057
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发表时间：
2019-07-15
影响因子：
22.1
通讯作者：
Sun, Jie
中科院分区：
文献类型：
--
作者：
Li, Qin;Zhao, Tingting;Sun, Jie
在过去的十年中，半导体稳定的皮克林乳液（PE）由于其高界面活性而得到了越来越多的认可。然而，由于大多数半导体本身具有强亲水性或疏水性表面，无法自行稳定PE微胶囊，因此在PE构建之前，用外来改性剂对半导体粉末表面进行预处理通常是不可避免和不方便的。更糟糕的是，添加的改性剂不可避免地限制了光催化过程中半导体与反应物之间的接触。在此过程中，无需对半导体进行预处理，一步即可成功制备出水包油PE，其中含染料废水和不溶性有机物分别作为水相和油相，水中的染料分子可以直接辅助TiO2颗粒成为稳定剂。制备的PE体系中TiO2粉末对染料的光降解活性明显高于传统的非乳化体系，且PE微胶囊易于回收再利用，无需严重破乳即可承受长期照射。本研究不仅为构建皮克林乳剂作为一种具有极高效率和可回收性的新型光催化体系提供了一种便捷而有前景的途径，而且为简化PE结构以满足未来实际应用的更多要求提供了新的思路。
Pickering emulsion (PE) stabilized by semiconductors for photocatalysis applications has received growing endorsement over the last decade due to its high interfacial activity. However, since most semiconductors inherently possess a strongly hydrophilic or hydrophobic surface and are unable to stabilize PE microcapsules by themselves, pretreating the surface of semiconductor powder with foreign modifier was usually unavoidable and inconvenient before the PE construction. Even worse, the added modifier inevitably limited the contact between the semiconductor and the reactant during the photocatalysis process. Herein, an oil-in-water PE was successfully obtained in one step without pretratment of the semiconductor, where the dye-contained wastewater and insoluble organic matter acted as the water and oil phases, respectively, and the dye molecules in water could directly assist TiO2 particles to become the stabilizer. The TiO2 powder in the formed PE system exhibited markedly enhanced photoactivity for dye degradation over that in traditional non-emulsified systems, and the PE microcapsules could be easily recovered for reuse and withstand long-term irradiation without severe demulsification. This work not only highlights a convenient and promising approach to build Pickering emulsion as a novel photocatalytic system with extremely high efficiency and recyclability, but also provides a new way of thinking on how to simplify the PE construction to meet more requirement in future practical applications.