Efficient photoelectrochemical sensor of Cu2+ based on ZnO-graphene nanocomposite sensitized with hexagonal CdS by calcination method

A novel ternary nanocomposite of CdSH/ZnO-GE was prepared for photoelectrochemical (PEC) selective sensing of Cu2+. ZnO nanorods and graphene (GE) nanosheets were first decorated on Ni foam (NF) simultaneously by a facile hydrothermal method and then CdS nanoparticles were loaded on ZnO-GE arrays through simple chemical bath deposition (CBD) method and following calcination process to form hexagonal CdS (CdSH). The obtained CdSH/ZnO-GE@NF sensor was characterized by scanning electron micrographs, X-ray diffraction and X-ray photoelectron spectroscopy. The CdSH/ZnO-GE@NF electrode exhibited enhanced photoelectrical activity with a photocurrent density of 6.8 mA center dot cm-2 under illumination at 0.5 V vs. SCE. For the PEC detection of Cu2+, the as-prepared sensor exhibited a low detection limit of 0.03 mu M and wide linear concentration rang of 0.2 mu M to 1 mM with high selectivity and stability. It was successfully applied to the detection of Cu2+ in real industrial waste water and sea water, suggesting that the CdSH/ZnO-GE@NF electrode is a promising sensor to detect copper pollution in natural environments.

Automated summary

A novel ternary nanocomposite of CdSH/ZnO-GE was prepared for photoelectrochemical sensing of Cu2+, showing enhanced photoelectrical activity and wide linear concentration range for detection. The sensor exhibited low detection limit, high selectivity and stability, making it promising for detecting copper pollution in natural environments.