An All-Solid-State Ti/RuO pH Electrode Prepared Based on the Thermal Oxidation Method

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Precise pH measurement is crucial for marine scientific research.
• All-solid-state electrodes offer advantages in stability and ease of use over traditional electrodes.
• Existing electrodes may face challenges with long-term stability and interference in complex water matrices.

Purpose of the Study:

• To develop a novel fabrication technique for an all-solid-state ruthenium oxide (Ti/RuO) pH electrode.
• To evaluate the performance and stability of the fabricated electrode for potential use in marine scientific applications.
• To assess the electrode's accuracy and reliability across various water sample types.

Main Methods:

• A novel fabrication method involving thin-coating of a ruthenium oxide precursor on a titanium wire substrate.
• Calcination and acid treatment to form the ruthenium oxide film.
• Comprehensive electrochemical characterization including response slope, linearity, response time, hysteresis, reversibility, and repeatability testing.
• Long-term stability, potential drift, interference resistance, and storage life assessments were conducted.

Main Results:

• The fabricated Ti/RuO electrode exhibited a dense, regular conical morphology.
• A near-Nernstian response slope (-59.04 mV/pH), high linearity (R² = 0.9999), rapid response (<1 s), and low hysteresis (<3 mV) were observed.
• Excellent long-term stability (0.27 mV/day drift over 25 days), robust interference resistance, and high accuracy (± 0.02 pH units) were demonstrated in seawater, freshwater, and tap water.

Conclusions:

• The novel fabrication technique successfully produced a high-performance all-solid-state ruthenium oxide pH electrode.
• The Ti/RuO electrode demonstrates superior performance characteristics, including stability, accuracy, and rapid response.
• This electrode shows significant potential as a reliable tool for precise pH measurements in marine scientific research and other applications.