Reliable and selective lead-ion sensor of sulfur-doped graphitic carbon nitride nanoflakes

An optimum large specific surface area of sulfur-doped graphitic carbon nitride nanoflakes modified glassy carbon electrode (S-g-C 3 N 4 /GCE) is reported with promising lead ion (Pb 2+ ) detection capability. This sensor was designed and fabricated using thermal polycondesation reaction . In terms of high selectivity Pb 2+ performance, we noted that the sensor exhibited appreciable detection limit of 3.0 × 10 −9  mol L −1 (S/N = 3) within the ionic specimen concentration range of 7.5 × 10 −8  ~ 2.5 × 10 −6  mol L −1 and 2.5 × 10 −6  ~ 1 × 10 −3  mol L −1 . Corroborated by DFT calculations, we propose that the strong interaction of S-g-C 3 N 4 interface and Pb 2+ plays an important role to generate the aforementioned sensing characteristics. In practice, we conceived high detection of Pb 2+ ions that reside in lake-water and mineral samples in which percentage recovery of 88–103 can be obtained under high repetition rate. Thus, S-g-C 3 N 4 /GCE can be considered as sensitive and selective electrochemical sensor for a reliable detecting heavy metal ions in domestic sewage and industrial wastewater.