一步电沉积石墨烯/纳米金复合物修饰电极及电化学检测Cr(Ⅵ)  

One-step electrodeposition graphene/gold nanocomposite modified electrodes for the electrochemical detection of Cr(Ⅵ)

作　　者：鲁子君 李博祎 唐海芳 刘承斌[1,2] LU Zijun;LI Boyi;TANG Haifang;LIU Chengbin(College of Chemistry and Chemical Engineering,Hunan University,Changsha 410082,China;College of Environment and Resources,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湖南大学化学化工学院,湖南长沙410082 [2]湘潭大学环境与资源学院,湖南湘潭411105

出　　处：《湘潭大学学报(自然科学版)》2025年第2期34-45,共12页Journal of Xiangtan University(Natural Science Edition)

基　　金：国家重点研发项目(2020YFC1807300);国家环境保护重金属污染监测重点实验室(SKLMHM202205);长沙市自然科学基金(kq2208013)。

摘　　要：六价铬(Cr(Ⅵ))是一种广泛存在于环境体系中的重金属离子,对人体有着很强的毒性,开发选择性检测Cr(Ⅵ)的技术,对保护环境和人类健康至关重要.该文通过一步电沉积法在玻碳电极(GCE)上原位生长石墨烯/纳米金复合物修饰电极(Au/RGO-GCE),通过差分脉冲伏安法对水体Cr(Ⅵ)进行检测.结果表明,在最佳条件下(富集电位为-0.9 V,富集时间为210 s,pH为6的醋酸钠-醋酸缓冲液),Au/RGO-GCE电极对浓度范围为5~95μg·L^(-1)的Cr(Ⅵ)进行检测,线性方程为Y=1.4389+0.01613 X,相关系数R^(2)=0.992,呈现良好的线性关系.基于3倍信噪比,计算得到Au/RGO-GCE电极对Cr(Ⅵ)的检出限为1μg·L^(-1).对同一电极进行连续9次测量,相对标准偏差为1.88%,水体中常见金属离子对检测影响较小,以实际水样进行加标回收检测时,回收率均保持在90%~110%之间,表明所制备电极具有较强的稳定性和抗干扰能力.将所制备电极搭配江苏天瑞仪器股份有限公司的便携式水质重金属分析仪,到广西壮族自治区柳州市某复合污染场地(经度109°379997″,纬度24°329288″)进行现场测试.10μg·L^(-1)和20μg·L^(-1)浓度Cr(Ⅵ)的加标回收测试中,回收率分别保持在95%~115%和100%~105%,表明所制备电极搭配便携式水质重金属分析仪被成功应用于地下水中Cr(Ⅵ)的现场原位检测.该文开发的Au/RGO电极具有巨大的应用前景,为地下水中Cr(Ⅵ)的现场快速检测提供了新途径.Cr(Ⅵ)is a kind of heavy metal ion widely existing in environmental system,which has strong toxicity to human body.The development of selective detection of Cr(Ⅵ)technology is of great importance to protect the environment and human health.In this paper,the graphene/gold nanocomposite(Au/RGO)modified electrode was in-situ grown on the glass carbon electrode by one-step electrodeposition,and Cr(Ⅵ)in water was detected by differential pulse voltammetry.The results show that under the optimal conditions(enrichment potential-0.9 V,enrichment time 210 s,pH=6 NaAc-HAc buffer),Au/RGO electrode was used to detect Cr(Ⅵ)in the concentration range of 5~95μg·L^(-1),and the linear equation was Y=1.4389+0.01613 X,correlation coefficient R^(2)=0.992,showing a good linear relationship.Based on the 3-fold signal-to-noise ratio,the detection limit of Cr(Ⅵ)by Au/RGO electrode was calculated to be 1μg·L^(-1).Then the same electrode was measured for nine consecutive times,the relative standard deviation was 1.88%,the common metal ions in the water had little influence on the detection,and the recovery rate was maintained between 90%and 110%when the actual water samples were added to the standard,indicating that the prepared electrode had strong stability and anti-interference ability.The prepared electrode was combined with the portable water heavy metal analyzer of Jiangsu Tianrui Instrument Co.,Ltd.to a compound contaminated site(longitude 109°379997",latitude 24°329288")in Liuzhou,Guangxi Zhuang Autonomous Region for field testing.The recoveries of 10μg·L^(-1) and 20μg·L^(-1) concentration Cr(Ⅵ)were maintained at 95%~115%and 100%~105%,respectively,indicating that the prepared electrodes combined with portable water quality heavy metal analysis instruments were successfully applied to the in-situ detection of Cr(Ⅵ)in groundwater.The Au/RGO electrode developed in this paper has a great application prospect and provides a new way for the rapid detection of Cr(Ⅵ)in groundwater.

关 键 词：Cr(Ⅵ) 差分脉冲伏安法 金纳米颗粒 还原氧化石墨烯 

分 类 号：O657.1[理学—分析化学] X853[理学—化学]