A novel chloride selective potentiometric sensor based on graphitic carbon nitride/silver chloride (g-C3N4/AgCl) composite as the sensing element

In this research, AgCl anchored graphitic carbon nitride (g-C3N4) was introduced as a novel potentiometric sensing element. A g-C3N4/AgCl-modified carbon paste electrode (CPE) was fabricated and used as an outstandingly selective potentiometric sensor to determine Cl- in water samples. The g-C3N4/AgCl nano composite was characterized with SEM, XRD and FT-IR techniques. It was demonstrated that, the incorporation of 5% of g-C3N4/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(-1), over a wide linear concentration range of 1 x 10(-6)-1 x 10(-1) mol L-1 and the detection limit of the electrode was estimated to be 4.0 x 10- 7 mol L-1. The g-C3N4/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-C3N4 on the sensor performance. This innovative electrode was shown to be a sensitive and accurate sensor for chloride ion content estimation in water samples.

Automated summary

By incorporating 5% of g-C3N4/AgCl as a chloride ionophore in a CPE, a highly selective and stable potentiometric sensor for chloride ion detection was developed, exhibiting fast response time, long-term stability, and a wide linear concentration range. This innovative electrode showed high sensitivity and accuracy in estimating chloride ion content in water samples.