Fabrication of Jello-Based Ag/AgCl Reference Electrode from Recyclable Resources to Enhance Undergraduate Laboratory Student Experience and its Promising Utilization in Corrosion and Electrochemical Sensing

Abstract

This paper presents a realistic approach to experience electrochemical principles in the context of an upper undergraduate research course where students will learn how to fabricate and calibrate a reference electrode (RE) which is an essential component of an electrochemical system. Among many commercially available REs, Ag/AgCl RE is one of the most employed REs in teaching laboratories and research. However, the REs fabrication and assembly pose technological challenges in addition to their cost especially for large quantities procurement for undergraduate laboratories. To circumvent these constraints, one alternative is to fabricate them in the lab, however, the use of harmful chemicals and complicated techniques limits their practical fabrication in teaching laboratories. Therefore, this study, devised a simple and cost-effective method for fabricating a homemade Ag/AgCl RE assembly where jello is used instead of a glass frit (referred as JRE) from recyclable and obsolete items available in common undergraduate laboratories. The as-fabricated jello RE exhibited excellent sensitivity and accuracy as compared to a commercially available BASi RE from the cyclic voltammetric (CV) studies. Subsequently, JRE showed its potential in two distinct electrochemical experiments, including potentiodynamic Tafel corrosion scans and electrochemical sensing and detection of Ascorbic Acid (AA). In addition to outstanding reproducibility, JRE demonstrated higher stability even after four months of storage in the refrigerator. Keywords: Undergraduate laboratories, Homemade reference electrode, recyclable wastes, corrosion, electrochemical detection