Titanium Nitride-based Ion Selective Electrode

pH is one of the most important parameters of aqueous samples and plays an important role in many areas such as industry, agriculture, biology, pharmaceutical industry, environmental protection and so on. The preparation of pH sensors has always been one of the major interests of the field of chemical sensors. Titanium nitride has high hardness and melting point, good resistance and corrosion resistance, chemical stability, excellent conductivity etc. Here titanium nitride is selected as pH-sensitive material and its pH response performance has also been discussed.1 The TiN electrode showed a linear response in the pH range of 11-14 with a response slope of -60 mV/pH. The correlation coefficient was 0.998. The response time was less than 1 min. It exhibits some advantages over the glass pH electrode inmore rigid structure and better selectivity toward cations of alkali metals, especially overcoming the interference of Na+ in high pH solution. The electrode also showed high stability and good reproducibility. The potential drifts of the electrode were less than 2mV as measured in pH 13.5 and 14 solutions for 2h. When the electrode was alternately measured in two solutions of pH 13.5 and 14, the relative standard deviation estimated for six measurements were about 0.27% and 0.29% respectively. In addition, the electrode performed excellently in corrosion medium containing F".2 The TiN electrode showed a linear response in the pH range of 2-12 with a response slope of-55mV/pH. The correlation coefficient was 0.997. No interferences from commonly accompanying cations and anions were observed. The electrode alsoshowed high stability and good reproducibility. It can be used in corrosion medium containing F-.The appended documents describe the electrochemical oxidation of ascorbic acid on TiN electrode and the pH response of polyaniline modified TiN electrode. TiN electrode has strong electro-catalytic effect on the oxidation of ascorbic acid. The anodic peak potential of ascorbic acid shifted negatively. Polyaniline modified TiN electrode exhibited a linear response in pH 4-10 with a slope of-39mV/pH.