Liu Dandan, Liu Xin, Guo Zhifen, Li Qiang, Yang Jian, Xing Hongzhu, Chen Dashu
College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, No. 26 Hexing Road, Harbin 150040, China.
Provincial Key Laboratory of Advanced Energy Materials, College of Chemistry, Northeast Normal University, No. 5268 Renmin Street, Changchun 130024, China.
Inorg Chem. 2023 Dec 4;62(48):19812-19820. doi: 10.1021/acs.inorgchem.3c03563. Epub 2023 Nov 21.
In this study, four isostructural aluminum-based porphyrin metal-organic frameworks [Al-TCPP(M), M = H and Zn] with different morphologies and sizes were synthesized by the hydrothermal method. By adjusting the hydrothermal reaction time and the types of porphyrin ligands, Al-TCPP(M) MOFs exhibited diverse morphologies including tetragonal, rectangular, and carambola-like phase. In view of the introduction of porphyrin ligands and the strong coordination effect of Al-O units, Al-TCPP(M) MOFs exhibited good chemical stability, broad visible light harvesting capability, and fast photogenerated charge response. Four Al-TCPP(M) MOFs exhibited excellent photocatalytic activities for Cr(VI) in aqueous solution. Notably, the regulation to the nanoscale carambola-like morphology of Al-TCPP MOFs and metallization of the porphyrin ligand promoted the Cr(VI) photoreduction reaction where the catalytic activity of metallic carambola-like Al-TCPP increased 1.7 times compared to that of nonmetallic tetragonal MOFs. With the assistance of sonophotocatalysis, the Cr(VI) average reduction rates reached 0.658, 0.542, 0.785, and 0.629 mg·L·min for Al-TCPP(H)-24h, Al-TCPP(H)-72h, Al-TCPP(Zn)-24h, and Al-TCPP(Zn)-72h, which are 1.2-1.4 times higher than that of photocatalysis. UV-vis absorption spectroscopy, electronic spin resonance, and fluorescence spectroscopy experiments demonstrated that the synergistic effect of photochemistry and sonochemistry promoted the transfer of photogenerated electrons from Al-TCPP(M) to Cr(VI), thus enhancing the catalytic activity. The combination of the sonophotocatalytic technology with aluminum-porphyrin MOFs may become an effective strategy to improve MOF-based photocatalytic systems.
在本研究中，通过水热法合成了四种具有不同形态和尺寸的同构铝基卟啉金属有机框架材料[Al-TCPP(M)，M = H和Zn]。通过调节水热反应时间和卟啉配体的类型，Al-TCPP(M)金属有机框架呈现出多种形态，包括四方相、矩形相和杨桃状相。鉴于卟啉配体的引入以及Al-O单元的强配位作用，Al-TCPP(M)金属有机框架表现出良好的化学稳定性、宽广的可见光捕获能力和快速的光生电荷响应。四种Al-TCPP(M)金属有机框架对水溶液中的Cr(VI)表现出优异的光催化活性。值得注意的是，对Al-TCPP金属有机框架的纳米级杨桃状形态的调控以及卟啉配体的金属化促进了Cr(VI)的光还原反应，其中金属杨桃状Al-TCPP的催化活性比非金属四方相金属有机框架提高了1.7倍。在声光催化的辅助下，Al-TCPP(H)-24h、Al-TCPP(H)-72h、Al-TCPP(Zn)-24h和Al-TCPP(Zn)-72h的Cr(VI)平均还原速率分别达到0.658、0.542、0.785和0.629 mg·L·min，比光催化高1.2 - 1.4倍。紫外可见吸收光谱、电子自旋共振和荧光光谱实验表明，光化学和声化学的协同效应促进了光生电子从Al-TCPP(M)转移到Cr(VI)，从而提高了催化活性。声光催化技术与铝卟啉金属有机框架的结合可能成为改善基于金属有机框架的光催化体系的有效策略。
