Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
J Colloid Interface Sci. 2018 Jul 15;522:174-182. doi: 10.1016/j.jcis.2018.03.075. Epub 2018 Mar 23.
Poor visible-light-driven activity and deactivation property as well as wide band gap of the most common TiO photocatalyst significantly limits its practical application in volatile organic compounds (VOCs) purification. In this study, tiny TiO nanoparticles incorporated into a typical metal-organic framework (MOF), NH-UiO-66, with controllable TiO content and size, were synthesized based on the hard-soft acid-base (HSAB) principle and applied to VOCs purification. Compared to bare TiO, the TiO@NH-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 TiO and NH-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 TiO. The TiO@NH-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 TiO and MOF. The TiO@NH-UiO-66 with 5 wt% TiO could efficiently mineralize styrene to CO to some extent companying with the removal ratio >99% within 600 min, whereas the removal efficiency over the bare TiO only 32.5%.
常见的 TiO 光催化剂可见光驱动活性和失活性能差以及宽带隙极大地限制了其在挥发性有机化合物 (VOCs) 净化中的实际应用。在本研究中，根据软硬酸碱 (HSAB) 原理，将微小的 TiO 纳米颗粒掺入具有可控 TiO 含量和尺寸的典型金属有机骨架 (MOF) NH-UiO-66 中，合成了 TiO@NH-UiO-66 复合材料，并将其应用于 VOCs 净化。与纯 TiO 相比，由于 TiO 和 NH-UiO-66 之间的优异界面接触，TiO@NH-UiO-66 复合材料可以将光吸收扩展到可见光范围，并加速光生电子-空穴分离。此外，外 MOF 的丰富互连 3D 腔允许 VOCs 容易扩散到孔中，在封装的 TiO 周围产生浓度微环境。TiO@NH-UiO-66 复合材料在可见光照射下光催化降解气态苯乙烯时表现出显著提高的光催化效率和良好的抗失活能力，这与 TiO 和 MOF 之间的协同效应有关。TiO@NH-UiO-66 中含有 5wt%TiO 的复合材料在 600min 内可在一定程度上将苯乙烯矿化为 CO，去除率>99%，而纯 TiO 的去除效率仅为 32.5%。
