CdS/TiC heterostructure-based photoelectrochemical platform for sensitive and selective detection of trace amount of Cu.

Photoelectrochemical (PEC) detection as a potential development strategy for Cu ion sensor has arisen extensive attention. Herein, CdS/TiC heterostructure was synthesized by electrostatically driven assembly and hydrothermal method. On the basis of a CdS/TiC heterostructure, a novel anodic PEC sensing platform was constructed for highly sensitive detection of trace amount of Cu. Carrier transport at the interface of CdS/TiC heterostructure was tremendously improved, due to the generation of effective Schottky junctions. Under visible light irradiation, the CdS/TiC heterostructure-modified PEC platform exhibits great anode photocurrent signal, and the formation of CuS reduces the PEC response with the presence of Cu as a representative analyte. Thus, the linear response of Cu ranges from 0.1 nM to 10 µM and the limits of detection (LOD, 0.05 nM) are obtained, which is lower than that of WHO's Guidelines for Drinking-water Quality (30 μM). This idea of component reconstitution provides a new paradigm for the design of advanced PEC sensors.