Zeama Mostafa, Morsy Mohamed A, Abdelnaby Mahmoud, Gutiérrez-Arzaluz Luis, Mohammed Omar F, Yamani Zain H
Department of Physics, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, 31261, Saudi Arabia.
Center of Research Excellence in Nanotechnology (CENT), Interdisciplinary Research Center for Hydrogen and Energy Storage (IRC-HES), King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, 31261, Saudi Arabia.
Chem Asian J. 2021 Sep 1;16(17):2520-2528. doi: 10.1002/asia.202100588. Epub 2021 Aug 4.
This study aims to investigate the effect of replacing Ti with Zr in the SBU of MIL-125-NH . We were able to replace Ti with Zr in the mixed metal synthesis of MIL-125-NH , for the first time. After experimentally confirming the consistency in their framework structure and comparing their morphology, we related the femtosecond light dynamics with photocatalytic CO visible light conversion yield of the different variants in order to establish the composition-function relation in MIL-125 vis a vis CO reduction. Introducing Zr to the system was found to cause structure defects due to missing linkers. The lifetime of the charge carriers for the mixed metal samples were shorter than that of the MIL-125-NH . The study of CO photocatalytic reduction under visible light indicated that the NH group enhances the photocatalytic activity while the Zr incorporation inside the MIL framework introduces no significant improvements. In addition, the material systems were modelled and simulated through DFT calculations which concluded that the decrease of the photocatalytic activity is not related to the system electronic structure, insinuating that defects are the culprit.
本研究旨在探究在MIL-125-NH的次级构筑单元中用Zr取代Ti的效果。我们首次在MIL-125-NH的混合金属合成中用Zr取代了Ti。在通过实验确认其骨架结构的一致性并比较它们的形态之后，我们将飞秒光动力学与不同变体的光催化CO可见光转化产率相关联，以便建立MIL-125中关于CO还原的组成-功能关系。发现将Zr引入该体系会由于连接体缺失而导致结构缺陷。混合金属样品的电荷载流子寿命比MIL-125-NH的短。可见光下CO光催化还原的研究表明，NH基团增强了光催化活性，而在MIL骨架内引入Zr并没有带来显著改善。此外，通过密度泛函理论（DFT）计算对材料体系进行了建模和模拟，结果表明光催化活性的降低与体系电子结构无关，这意味着缺陷是罪魁祸首。
