Enhanced visible-light photocatalytic activity to volatile organic compounds degradation and deactivation resistance mechanism of titania confined inside a metal-organic framework.
Enhanced visible-light photocatalytic activity to volatile organic compounds degradation and deactivation resistance mechanism of titania confined inside a metal-organic framework.
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DOI：
10.1016/j.jcis.2018.03.075
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发表时间：
2018-07
影响因子：
9.9
通讯作者：
Peng Yao;Hongli Liu;Dong-Ting Wang;Jiangyao Chen;Guiying Li;T. An
中科院分区：
文献类型：
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作者：
Peng Yao;Hongli Liu;Dong-Ting Wang;Jiangyao Chen;Guiying Li;T. An
最常见的TiO 2光催化剂可见光驱动活性和失活性能较差，且带隙较宽，严重限制了其在挥发性有机物（VOCs）净化中的实际应用。本研究基于软硬酸碱（HSAB）原理合成了纳米TiO 2颗粒，并将其应用于VOCs的净化。与裸TiO 2相比，由于TiO 2与NH 2-UiO-66之间良好的界面接触，TiO2@NH2-UiO-66复合材料的光吸收范围扩展到可见光范围，加速了光生电子-空穴的分离。此外，外部MOF的丰富的互连3D空腔允许VOC容易地扩散到孔隙中，从而在封装的TiO 2周围产生浓度微环境。在可见光照射下，TiO2@NH2-UiO-66复合材料光催化降解气态苯乙烯时，表现出明显的光催化效率和良好的抗失活能力，这与TiO 2和MOF之间的协同效应有关。TiO 2质量分数为5%的TiO2@NH2-UiO-66催化剂可在一定程度上矿化苯乙烯，600 min内去除率>99%，而裸TiO 2催化剂的去除率仅为32.5%。
Poor visible-light-driven activity and deactivation property as well as wide band gap of the most common TiO2photocatalyst significantly limits its practical application in volatile organic compounds (VOCs) purification. In this study, tiny TiO2nanoparticles incorporated into a typical metal-organic framework (MOF), NH2-UiO-66, with controllable TiO2content and size, were synthesized based on the hard-soft acid-base (HSAB) principle and applied to VOCs purification. Compared to bare TiO2, the TiO2@NH2-UiO-66 composites could extend the optical absorption to the visible light range and accelerate the photogenerated electrons-holes separation, due to the excellent interface contact between TiO2and NH2-UiO-66. Moreover, the abundant interconnected 3D cavities of the outer MOF allowed for VOCs to easily diffuse into the pores, producing a concentration microenvironment around the encapsulated TiO2. The TiO2@NH2-UiO-66 composites exhibited a markedly improved photocatalytic efficiency and a good resistance to deactivation during the photocatalytic degradation of gaseous styrene under visible light illumination, which were associated with the synergetic effects between the TiO2and MOF. The TiO2@NH2-UiO-66 with 5 wt% TiO2could efficiently mineralize styrene to CO2to some extent companying with the removal ratio >99% within 600 min, whereas the removal efficiency over the bare TiO2only 32.5%.