Evaluation of mesoporous borosilicate glass-ceramic composites as frits in reference electrodes

The development of new mesoporous frits for reference electrodes to overcome the limitations of cross-contamination and screening effect is essential for many electrochemical measurements. Available frit-based reference electrodes (e.g., mesoporous, microporous) still suffer from cross-contamination and/or errors in electrochemical measurements. In this work, a mesoporous glass-ceramic composite is prepared to mitigate such limitations. Mesoporous glass-ceramic frits were prepared from low-cost materials (i.e., borosilicate and kaolin) at relatively low temperatures (750-850 degrees C). The prepared glass-ceramic frits were characterized using scanning electron microscopy (SEM), impedance measurements, and nitrogen sorption isotherms. The developed mesoporous glass-ceramic composites are characterized by a high chemical resistance against corrosive materials and a low thermal expansion. Reference electrodes constructed with the developed mesoporous glass-ceramic frits exhibited a low flow rate of 0.002 +/- 0.001 to 0.41 +/- 0.06 mu L h(-1) and high potential stability as well as very small potential drift of -2.4 +/- 0.2 to -4.9 +/- 0.2 mu V h(-1). Mesoporous glass-ceramic based reference electrodes exhibited average potential variations of 13 +/- 3 mV over the concentration range of 1 mM to 0.1 M KCl. This indicates that mesoporous glass-ceramic frit-based reference electrodes exhibited a much lower flow rate compared to available microporous frit-based reference electrodes. Moreover, the developed mesoporous ceramic-based reference electrodes exhibited a 4-15-fold improvement in potential variations and a large improvement in potential stability in comparison with the reported mesoporous-frit-based reference electrodes.

Automated summary

The development of mesoporous glass-ceramic frits for reference electrodes is crucial in overcoming the limitations of cross-contamination and screening effect in electrochemical measurements. These glass-ceramic frits exhibit low flow rates, high potential stability, and small potential drift, providing significant improvements compared to existing frit-based reference electrodes.