A novel photoelectrochemical sensor based on g-C3N4@CdS QDs for sensitive detection of Hg2+

Abstract Graphite carbonitride (g-C3N4) is one of the ideal metal-free semiconductors for photocatalysis, quantum dots are excellent photoelectrically active materials, and both have broad application prospects in photoelectrochemical (PEC) devices. In this work, a novel photoelectrochemical (PEC) sensor was latest employed based on the complex of g-C3N4 and CdS QD (g-C3N4@CdS) fixated on a tin oxyfluoride (FTO) electrode for discovering Hg2+. The PEC system showed a good linear range of 20–550 nM, with a detection limit of 12 nM. The possible mechanism is signal shutdown strategy based on a lower sedimentation equilibrium constant of HgS. Thus, the g-C3N4@CdS based PEC sensor had positive effect on solving some issues, such as complicated operation, in the detection of Hg2+.