Li Mei, Li Junke, Jin Zhiliang
School of Chemistry and Chemical Engineering, North Minzu University, Yinchuan 750021, P.R. China.
Dalton Trans. 2020 Apr 28;49(16):5143-5156. doi: 10.1039/d0dt00271b. Epub 2020 Apr 1.
A novel zero-dimensional/two-dimensional CdZnS/Ni-MOF-74 (CZS/NMF) heterojunction was rationally constructed via a simple hydrothermal and physical mixing method. The results show that the CZS/NMF-4 composite has the best photocatalytic hydrogen evolution performance, generating 1712.3 μmol of hydrogen within 5 h, approximately 10 times higher than the amount generated by pure CZS. This extraordinary enhanced photocatalytic hydrogen activity can be ascribed to the constitution of the direct Z-scheme heterojunction and the small size effect, as well as the intimate contact between the 0D CdZnS nanoparticles and the 2D Ni-MOF-74 sheets. The formation of the direct Z-scheme heterojunction can effectively reduce the migration resistance of light-generated carriers and dramatically promote the separation of photo-induced electrons and holes. Meanwhile, the size effect shortens the electron transfer distance which effectively decreases the recombination possibility of photo-induced electron-hole pairs. Furthermore, the 0D/2D spatial structure of CZS/NMF-4 dramatically reduces the agglomeration of CZS nanoparticles, which provides more active sites for the process of hydrogen evolution. In general, this work provides new inspiration for the application of combinations between progressively developing new MOF materials and the traditional CdZnS photocatalyst according to the construction of a special spatial structure.
通过简单的水热和物理混合方法合理构建了一种新型的零维/二维CdZnS/Ni-MOF-74（CZS/NMF）异质结。结果表明，CZS/NMF-4复合材料具有最佳的光催化析氢性能，在5小时内产生1712.3μmol氢气，约为纯CZS产生量的10倍。这种非凡的光催化析氢活性增强可归因于直接Z型异质结的构成和小尺寸效应，以及零维CdZnS纳米颗粒与二维Ni-MOF-74片层之间的紧密接触。直接Z型异质结的形成可以有效降低光生载流子的迁移阻力，并显著促进光生电子和空穴的分离。同时，尺寸效应缩短了电子转移距离，有效降低了光生电子-空穴对的复合可能性。此外，CZS/NMF-4的零维/二维空间结构显著减少了CZS纳米颗粒的团聚，为析氢过程提供了更多活性位点。总的来说，这项工作为根据特殊空间结构的构建，将逐步开发的新型MOF材料与传统CdZnS光催化剂相结合的应用提供了新的思路。
