Deng En-Ze, Fan Yan-Zhong, Wang Hai-Ping, Li Yuying, Peng Chao, Liu Jiewei
School of Environmental and Chemical Engineering, Jiangmen Key Laboratory of Synthetic Chemistry and Cleaner Production, Wuyi University, Jiangmen 529020, P. R. China.
Institute of Carbon Peaking and Carbon Neutralization, Wuyi University, Jiangmen 529020, P. R. China.
Inorg Chem. 2024 Jan 15;63(2):1449-1461. doi: 10.1021/acs.inorgchem.3c03968. Epub 2024 Jan 2.
Constructing a Z-scheme heterostructure on a metal-organic framework (MOF) composite with an explicit charge transfer mechanism at the interface is considered to be an effective strategy for improving the photocatalytic performance of MOFs. Herein, an internal electric field (IEF)-induced Z-scheme heterostructure on the ZnInS@NH-MIL-125 composite is designed and fabricated by a facile electrostatic self-assembly process. Systematic investigations reveal that close interfacial contact and difference in work function between NH-MIL-125 and ZnInS enable the formation of the IEF, which drives the Z-scheme charge transfer as revealed by the in situ irradiated X-ray photoelectron spectroscopy (ISI-XPS), photoirradiated Kelvin probe force microscope (KPFM) measurement, electron paramagnetic resonance (EPR) radical trapping experiment, as well as density functional theory (DFT) calculation; meanwhile, directions of the interfacial IEFs are determined. Benefiting from the unique merit of IEF-induced Z-scheme charge transfer, the optimized ZnInS@NH-MIL-125 composite exhibits significantly enhanced photocatalytic activity for the photoreduction of 4-nitroaniline (4-NA) to -phenylenediamine (PPD) under visible light irradiation. This work not only provides in-depth insights for charge transfer in the IEF-induced Z scheme heterostructure but also affords useful inspirations on designing the Z-scheme MOF composite to boost the photocatalytic performance.
在金属有机框架（MOF）复合材料上构建具有明确界面电荷转移机制的Z型异质结构被认为是提高MOF光催化性能的有效策略。在此，通过简便的静电自组装过程设计并制备了ZnInS@NH-MIL-125复合材料上的内建电场（IEF）诱导Z型异质结构。系统研究表明，NH-MIL-125和ZnInS之间紧密的界面接触和功函数差异促使了IEF的形成，原位辐照X射线光电子能谱（ISI-XPS）、光辐照开尔文探针力显微镜（KPFM）测量、电子顺磁共振（EPR）自由基捕获实验以及密度泛函理论（DFT）计算均表明该IEF驱动了Z型电荷转移；同时，确定了界面IEF的方向。得益于IEF诱导Z型电荷转移的独特优点，优化后的ZnInS@NH-MIL-125复合材料在可见光照射下对4-硝基苯胺（4-NA）光还原为对苯二胺（PPD）表现出显著增强的光催化活性。这项工作不仅为IEF诱导Z型异质结构中的电荷转移提供了深入见解，也为设计Z型MOF复合材料以提高光催化性能提供了有益的启发。
