A Photoelecteochemical Sensor Based on CdS Sensitized Fe : TiO2 Nanosheets for Determination of Cu2+

Iron-doped titanium dioxide nanosheets was prepared by hydrothermal method using tetrabutyl titanate (C16H36O4Ti) and iron trifluoride (FeF3) and modified on ITO electrode. ITO/Fe: TiO2/CdS photoelectrochemical sensor was fabricated by successive ionic layer absorption and reaction (SILAR) method for determination of copper ion. The band gap of electode material was narrowed by iron doped TiO2 nanosheets, which made its absorption red-shifted and its response range of light was magnified. Based on the sensitization effect of CdS, the absorption and utilization of visible light of sensor was significantly enhanced and the photoelectric signal was amplified via reducing the recombination of electrons and holes. The sensor displayed excellent analytical performance for detection of copper ion with linear range of 0.2-4.0 mu mol/L and 4.0-80.0 mu mol/L and with the detection limit of 85 nmol/L. The sensor was used to detect copper ion in tap water, drinking water and Yongjiang river water with recoveries ranging from 94% to 111%.