Cu ions anchored in the porphyrin center act as transient metal centers of 2D-MOFs to enhance photocatalytic hydrogen production
Cu ions anchored in the porphyrin center act as transient metal centers of 2D-MOFs to enhance photocatalytic hydrogen production
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DOI：
10.1039/d2cy01766k
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发表时间：
2022-12-12
影响因子：
5
通讯作者：
Liu, Xingyan
中科院分区：
文献类型：
--
作者：
Chen, Mingzuo;Zhang, Chenghua;Liu, Xingyan
为了提高电荷转移效率，在二维钛基卟啉mof中，非贵金属Cu锚定在卟啉中心，实现了一种新的配体到连接体的金属电荷转移（LLMCT）过程。实验结果表明，2D Cu-PTM具有最佳的析氢活性(5465.689 mu mol g(-1) h(-1))，是原始2H-PTM (197.224 mu mol g（-1) h(-1)）的27.71倍。一系列表征测试，特别是Auger Cu LMM和ESR，证明了瞬态Cu- i /Cu- ii中心在新的LLMCT过程中发挥了重要作用。简而言之，电子可以从受激的伊红Y （EY*）转移到卟啉的最低未占据分子轨道（LUMO）能级，然后通过卟啉单元的快速共轭离域18 π电子系统转移到瞬态Cu-I/Cu-II中心，进一步加快载流子分离和转移速率。本工作提供了更简单有效的策略来锚定二维卟啉mof中的过渡元素，并使用非贵金属离子作为低成本的辅助催化剂来提高光催化析氢性能。
To improve charge transfer efficiency, non-noble metal Cu anchored in the porphyrin center can realize a new ligand-to-linker metal charge-transfer (LLMCT) process in 2D Ti-based porphyrin MOFs. Experimental results demonstrate that 2D Cu-PTM has the best hydrogen evolution activity (5465.689 mu mol g(-1) h(-1)), which is about 27.71 times the value of original 2H-PTM (197.224 mu mol g(-1) h(-1)). A series of characterization tests, particularly Auger Cu LMM and ESR, proved that the transient Cu-I/Cu-II center played an important role in the new LLMCT process. In brief, electrons can transfer from excited eosin Y (EY*) to the lowest unoccupied molecular orbital (LUMO) level of porphyrin and then transfer to the transient Cu-I/Cu-II center via a fast conjugated delocalized 18-pi electron system of the porphyrin unit, which further accelerates the carrier separation and transfer rate. This work provides simpler and more effective tactics to anchor transition elements in 2D porphyrin MOFs and used non-noble metal ions as low-cost auxiliary catalysts to improve photocatalytic hydrogen evolution performance.