Enhancing the spatial separation of photogenerated charges on Fe-based MOFs via structural regulation for highly-efficient photocatalytic Cr(VI) reduction.
Enhancing the spatial separation of photogenerated charges on Fe-based MOFs via structural regulation for highly-efficient photocatalytic Cr(VI) reduction.
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DOI：
10.1016/j.jhazmat.2022.129875
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发表时间：
2022-08
影响因子：
13.6
通讯作者：
Hao Zhang;Yu-Hui Luo;Feng-Yu Chen;Wu Geng;Xinrong Lu;Dongen Zhang
中科院分区：
文献类型：
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作者：
Hao Zhang;Yu-Hui Luo;Feng-Yu Chen;Wu Geng;Xinrong Lu;Dongen Zhang
虽然铁基金属有机骨架材料（Fe-MOFs）已经显示出了良好的光催化活性，但通过结构调整来提高其光催化性能仍有很大的空间。本论文通过配体调控的方法成功合成了四种新型的铁基金属有机骨架（Fe-MOFs），其中MTBDC-TPT-Fe的催化活性最高（MTBDC = 2，5-二（甲硫基）对苯二甲酸，TPT = 2，4，6-三（4-吡啶基）-1，3，5-三嗪）。铁氧团簇与有机配体之间的电子推拉效应增强是促进光催化还原反应的主要原因。在可见光照射下，-SCH 3基团的引入可以增强光吸收并向铁中心提供电子，同时TPT的引入可以通过电子牵引效应促进光生载流子的分离和转移。此外，由于TPT的引入而增强的比表面积和正骨架电荷可以改善活性位点暴露和Cr（VI）吸附，从而在不存在任何辅助清除剂的情况下增强光催化Cr（VI）还原活性。此外，还对光催化反应的机理（即活性物种）进行了研究和介绍。本工作证实了Fe-MOFs光催化还原Cr（VI）的有效结构-性能调控策略。
Although iron-based metal-organic frameworks (Fe-MOFs) have displayed the photocatalytic activity, there is still abundant room for improving their photocatalytic performance through tuning the structures. In this work, four novel iron-based metal-organic frameworks (Fe-MOFs) were successfully synthesized via ligand modulation for better photocatalytic Cr(VI) reduction, in which MTBDC-TPT-Fe had the highest catalytic activity (MTBDC = 2,5-bis(methylthio)terephthalic acid, TPT = 2,4,6-tri(4-pyridyl)− 1,3,5-triazine). The boosted photocatalytic reduction may be mainly ascribed to the enhanced electron push-pull effect between iron-oxygen clusters and organic ligands. The introduction of -SCH3groups can enhance the light absorption and donate electrons to iron center under visible-light irradiation, meanwhile the separation and transfer of photogenerated charge carriers can be enhanced resulting from the electron-pulling effect when introducing TPT. Moreover, enhanced specific surface areas and positive skeleton charge due to the introduction of TPT may improve active sites exposure and Cr(VI) adsorption, thereby enhancing photocatalytic Cr(VI) reduction activity without the presence of any assisted scavengers. In addition, the photocatalytic mechanism (i.e. active species) were also studied and presented. This work confirmed an effective structure-performance regulation strategy on Fe-MOFs for photocatalytic Cr(VI) reduction.