基于CdS敏化Fe:TiO2纳米片的光电传感器对Cu2+的检测

摘要

以钛酸四丁酯(C16H36O4Ti)和三氟化铁(FeF3)为原料,用水热法制备了铁掺杂二氧化钛(TiO2)纳米片,并将其修饰ITO电极表面.通过连续离子吸附与反应(SILAR)法制备了ITO/Fe:TiO2/CdS光电传感器,并用于Cu2+的检测.Fe3+的掺杂使TiO2的带隙宽度变窄,对光的吸收产生红移,基于CdS的敏化效应,与TiO2结合后拓宽了可见光的吸收利用率,降低了电子-空穴的复合率,使光电信号显著增强.在0.2~4.0μmol/L和4.0~80.0μmol/L范围内,Cu2+浓度与传感器检测的电流值呈良好的线性关系,检出限为85nmol/L(S/N=3).将传感器分别用于桶装水、自来水、邕江水中Cu2+的测定,加标回收率为94%~111%.%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 μmol/L and 4.0-80.0 μmol/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%.