ZnO/CdS Hierarchical Nanospheres for Photoelectrochemical Sensing of Cu²⁺

ZnO/CdS hierarchical nanospheres were prepared for photoelectrochemical selective sensing of Cu 2+ . Hierarchical ZnO nanospheres were first synthesized by the hydrolysis of zinc salt under ultrasound irradiation, and then CdS nanocrystals were selectively grown on the hierarchical ZnO nanospheres. The light scattering of ZnO nanospheres and the heterointerfaces between CdS and ZnO provided significant advantages for enhanced light absorption and charge separation, thus resulting in an improvement in the photocurrent intensity. A photoelectrochemical sensor was developed based on the interaction between Cu 2+ and CdS. The results showed that this sensor has a good selectivity and high sensitivity for Cu 2+ detection.