A titanium nitride nanotube array for potentiometric sensing of pH

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Development of advanced electrode materials is crucial for accurate pH sensing.
• Titanium nitride nanotube arrays (TiN NTA) offer unique structural and electrochemical properties.

Purpose of the Study:

• To fabricate and characterize a TiN NTA electrode for pH sensing.
• To evaluate the performance of the TiN NTA electrode in terms of sensitivity, selectivity, stability, and response time.

Main Methods:

• Fabrication of TiN NTA via anodic oxidation of titanium and reduction/nitridation of TiO2 NTA.
• Characterization of TiN NTA microstructure (inner diameter, wall thickness, length).
• Open-circuit potential measurements to assess pH sensitivity, response time, stability, selectivity, hysteresis, and reproducibility across a pH range of 2.0-11.0.

Main Results:

• Uniform TiN NTA microstructure with specific dimensions (120 nm inner diameter, 15-20 nm wall thickness, 10 μm length).
• Near-Nernstian slope of 55.33 mV/pH with a high correlation coefficient (0.995).
• Excellent selectivity for H+ ions, good stability, reproducibility, and a fast response time of 4.4 seconds.

Conclusions:

• The fabricated TiN NTA electrode exhibits high performance for pH sensing.
• The electrode's properties make it a strong candidate for practical pH sensor applications.