A novel chloride selective potentiometric sensor based on graphitic carbon nitride/silver chloride (g-CN/AgCl) composite as the sensing element.

In this research, AgCl anchored graphitic carbon nitride (g-CN) was introduced as a novel potentiometric sensing element. A g-CN/AgCl-modified carbon paste electrode (CPE) was fabricated and used as an outstandingly selective potentiometric sensor to determine Cl in water samples. The g-CN/AgCl nanocomposite was characterized with SEM, XRD and FT-IR techniques. It was demonstrated that, the incorporation of 5% of g-CN/AgCl, as a chloride ionophore in a CPE, results in a stable potential response of the electrode to chloride ion. The Nernstian slope of the electrode response was 55.4 (±0.3) mVdecade, over a wide linear concentration range of 1 × 10-1 × 10 mol L and the detection limit of the electrode was estimated to be 4.0 × 10 mol L. The g-CN/AgCl-modified CPE electrode provided fast response time and long-term stability (more than 2 months) while the potential interfering ions such as I, Br, and CN showed no significant effect on the potential response. Since these interfering ions affected the response of the CPE electrode, modified with AgCl, highlighting the interesting effect of g-CN on the sensor performance. This innovative electrode was shown to be a sensitive and accurate sensor for chloride ion content estimation in water samples.