Qiu Jianhao, Zhang Xiong-Fei, Zhang Xingguang, Feng Yi, Li Yuxin, Yang Lvye, Lu Haiqiang, Yao Jianfeng
College of Chemical Engineering, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
School of Chemical and Biological Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China.
J Hazard Mater. 2018 May 5;349:234-241. doi: 10.1016/j.jhazmat.2018.02.009. Epub 2018 Feb 5.
A novel and highly efficient photocatalyst of CdZnS@ZIF-8 nanocomposite has been developed by a facile self-assembly strategy. This is the first report on the application of CdZnS and metal-organic framework (MOF) nanocomposite as photocatalysts for the reduction of Cr(VI). The resulting CdZnS@ZIF-8 exhibited higher photocatalytic activity than that of pristine CdZnS and ZIF-8. Particularly, the CZS@Z60 composite with 60 wt% of ZIF-8 exhibited a photocatalytic activity that is about 1.6 times as high as that of CdZnS. The dominant reason for the improved photocatalytic reduction potential is proved to be the newly-formed interfacial SZn bonds that firmly connect CdZnS and ZIF-8 and substantially improve the separation efficiency of photo-excited electrons and holes. The newly-formed chemical bonds are confirmed by XPS analyses, and the prolonged lifetime of photo-excited electrons is evidenced by the electrochemical measurement of photocurrent, which shows that the photocurrent on CdZnS@ZIF-8 is much higher than that of CdZnS and ZIF-8. This study clearly demonstrates that the MOF-based composite nanomaterials hold great promises for applications in the field of environmental remediation and for design of novel photocatalytic materials.
通过一种简便的自组装策略，开发了一种新型高效的CdZnS@ZIF-8纳米复合材料光催化剂。这是首次报道将CdZnS与金属有机框架（MOF）纳米复合材料用作光催化剂来还原Cr(VI)。所得的CdZnS@ZIF-8表现出比原始CdZnS和ZIF-8更高的光催化活性。特别是，含有60 wt% ZIF-8的CZS@Z60复合材料表现出的光催化活性约为CdZnS的1.6倍。光催化还原电位提高的主要原因被证明是新形成的界面S-Zn键，它牢固地连接了CdZnS和ZIF-8，并显著提高了光生电子和空穴的分离效率。新形成的化学键通过XPS分析得到证实，光生电子寿命的延长通过光电流的电化学测量得到证明，结果表明CdZnS@ZIF-8上的光电流远高于CdZnS和ZIF-8。这项研究清楚地表明，基于MOF的复合纳米材料在环境修复领域的应用以及新型光催化材料的设计方面具有巨大潜力。
