Microporous Ag/AgCl on a Titanium Scaffold for Use in Capillary Reference Electrodes.

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Silver/silver chloride (Ag/AgCl) reference electrodes are crucial in electrochemistry.
• Traditional fabrication methods face challenges with reproducibility and cost.
• Platinum and rhodium scaffolds are effective but prohibitively expensive.

Purpose of the Study:

• To investigate the stability and performance of Ag/AgCl reference electrodes fabricated using a thermal-electrolytic method on a titanium scaffold.
• To evaluate the suitability of these Ti/Ag/AgCl constructs for capillary-based reference electrodes.

Main Methods:

• Fabrication of Ti/Ag/AgCl constructs using the thermal-electrolytic method.
• Electrochemical characterization, including pH dependence and potential stability measurements.
• Assessment of electrical resistance and exchange current density.
• Testing in capillary-based reference electrodes with small sample volumes.

Main Results:

• The Ti/Ag/AgCl constructs exhibit stable and reproducible reference electrode performance.
• The half-cell potential remains pH-independent over a wide range.
• Low electrical resistance and high exchange current density were observed.
• Capillary-based electrodes demonstrated exceptionally low potential drifts (0.03 ± 2.01 μV/h) and minimal standard deviation (±0.5 mV over 60 h).

Conclusions:

• Titanium is a viable and cost-effective scaffold material for thermal-electrolytic fabrication of Ag/AgCl reference electrodes.
• These electrodes offer superior stability, reproducibility, and performance for capillary-based applications.
• The developed electrodes are suitable for precise measurements in small sample volumes while preventing contamination.