Electrogenerated chemiluminescence behavior of graphite-like carbon nitride and its application in selective sensing Cu ²⁺

This paper reports for the first time the electrogenerated chemiluminescence (ECL) behavior of graphite-like carbon nitride (g-C ₃N ₄) with K ₂S ₂O ₈ as the coreactant. The possible ECL reaction mechanisms are proposed. The spectral features of the ECL emission and photoluminescence (PL) of g-C ₃N ₄ are compared, and their resemblance demonstrates that the excited states of g-C ₃N ₄ from both ECL and photoexcitation are the same. The effects of K ₂S ₂O ₈ concentration, pH, g-C ₃N ₄/carbon powder ratio, and scan rate on the ECL intensity have been studied in detail. Furthermore, it is observed that the ECL intensity is efficiently quenched by trace amounts of Cu ²⁺. g-C ₃N ₄ is thus employed to fabricate an ECL sensor which shows high selectivity to Cu ²⁺ determination. The limit of detection is determined as 0.9 nM. It is anticipated that g-C ₃N ₄ could be a new class of promising material for fabricating ECL sensors.