基于碱式碳酸钴纳米棒构筑的电化学传感器对水样中镉离子的快速检测研究

Rapid determination of trace cadmium ion in water samples by electrochemical sensor based on cobalt carbonate hydroxide nanorods

通过制备不同粒径的碱式碳酸钴(CoCH)纳米材料,成功构筑了基于CoCH的电化学传感器。采用扫描电子显微镜-X射线能谱仪(SEM-EDS)和X射线衍射(XRD)对不同粒径尺寸的CoCH进行了表征,并通过循环伏安法(CV)以及方波伏安法(SWV)研究了镉的电化学行为。在确定滴涂量3μL、缓冲溶液的pH 5.0、沉积电位-1.0 V、沉积时间120 s的最佳电化学检测条件后,采用溶出伏安法得到Cd2+的氧化峰电流与Cd2+的浓度在0.2μmol·L^(-1)~7.1μmol·L^(-1)和7.1μmol·L^(-1)~80μmol·L^(-1)范围内呈良好线性,线性回归方程分别为:Ipa/μA=0.9577c/μmol·L^(-1)-0.08012(R^(2)=0.9972)和Ipa/μA=1.099c/μmol·L^(-1)+4.5273(R^(2)=0.9820)。检出限为6.67×10^(-8)mol·L^(-1)(S∶N=3∶1)。该方法简便、灵敏、快速,重现性和选择性好,无需复杂的样品前处理,实现了实际水样中镉的快速测定,回收率在87.00%~110.17%,有望应用于工业废水中镉的快速检测。

Cobalt Carbonate Hydroxide(CoCH)based electrochemical sensors were successfully constructed by using CoCH nanorods with different particle sizes.CoCH with different particle size was characterized by scanning electron microscopy-X-ray energy dispersive spectrometer(SEM-EDS)and X-ray diffraction(XRD),and the electrochemical behavior of cadmium was studied by cy-clic voltammetry(CV)as well as square wave voltammetry(SWV).After optimizing the electrochemical detection conditions with the titer of 3μL,the pH 5.0 of the buffer solution,the deposition potential of?1.0 V,and the deposition time of 120 s,the oxidation peak current of Cd2+obtained by dissolution voltammetry showed good linearity with the concentration of Cd2+in the range of 0.2μmol·L^(-1)~7.1μmol·L^(-1)and 7.1μmol·L^(-1)~80μmol·L^(-1),and the linear regression equations respectively were:Ipa/μA=0.9577c/μmol·L^(-1)-0.08012(R^(2)=0.9972)and Ipa/μA=1.099c/μmol·L^(-1)+4.5273(R^(2)=0.9820).The detection limit was 6.67×10^(-8)mol·L^(-1)(S∶N=3∶1).The detection method is simple,sensitive,rapid,reproducible and selective,without complex sample pretreatment,and realizes the rapid determination of cadmium in actual water samples with recoveries of 87.00%~110.17%,which is expected to be applied to the rapid detection of cadmium in industrial wastewater.