Hands-On Approach to Structure Activity Relationships of Substituted MIL-101(Fe)-X Nanozymes: Synthesis, Characterization, and Hammett Analysis

A comprehensive laboratory-style teaching activity involving the synthesis, characterization, and analysis of structure–activity relationships of metal–organic framework (MOF) nanozymes was developed specifically for undergraduates at Tianjin University. The students acquired familiarity with the general approach in synthesizing MOFs by solvothermal method using substituted MIL-101(Fe)-X (MIL is an acronym for Materials of Institute Lavoisier). Several modern characterization methods were taught, including powder X-ray diffraction and fluorescence spectroscopy for assessing MIL-101(Fe)-X crystal structures and superoxide dismutase (SOD)-like activities. In particular, students were guided by the instructor to investigate the relationship between structural differences in MOFs caused by ligand changes and their SOD-like activities. The Hammett relationships were later demonstrated to be an accurate method of quantifying structure–activity relationships of MIL-101(Fe)-X nanozymes. By participating in this laboratory experience, students are able to improve their scientific thinking, practical abilities, and teamwork. Additionally, a fundamental principle of material design can be conveyed to undergraduates based on the structure–activity relationship, thereby deepening their understanding of nanozymes and the course's content.