Exploring Electrochemistry: A Self-Designed Experiment by Students for Electrochemical Impedance Spectroscopy Measurement of Hollow Fiber Membranes

Electrochemical impedance spectroscopy (EIS), as a valuable analytical technique for exploring material properties and electrochemical reactions, occupies an important position in multiple scientific disciplines. However, students often face challenges in bridging the gap between theoretical principles and practical applications of EIS. Conventional experimental teaching protocols often focus on measuring known samples under established operating parameters. Although this method is effective in imparting basic knowledge, it may not fully cultivate students' ability to conduct hands-on experiments and further foster their critical thinking and solving practical problems independently. Our experiment encourages students to design EIS experimental equipment and develop their own problem-solving oriented strategies. The core of this experimental design is to use hollow fiber membranes with different structures as test samples. Compared with flat sheet membranes, which have been frequently applied for EIS measurements, the characterization and analysis of hollow fiber membranes through EIS remain an underexplored area, offering a trove of possibilities for innovative research. In the laboratory, students showcase their designed EIS monitoring devices tailored to the unique characteristics of hollow fiber membranes. Subsequently, students collected and interpreted impedance spectra under a series of experimental conditions, including exploring the effects of electrodes made of various materials and electrolyte with different concentrations and further conducting error analysis, which are summarized in the final experimental report. The feedback from students after the experiment emphasized that the experiment based on an interactive design significantly improved their interest and mastery of EIS technology. By combining theoretical insights with practical applications, this methodology has effectively spanned the divide between academic studies and the resolution of real-world challenges.