College of Artificial Intelligence, Nanjing Agricultural University, Nanjing 210031, China.
Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
Sensors (Basel). 2020 Oct 26;20(21):6085. doi: 10.3390/s20216085.
In this paper, bismuth subcarbonate (BiO)CO-reduced graphene oxide nanocomposite incorporated in Nafion matrix ((BiO)CO-rGO-Nafion) was synthesized and further applied, for the first time, in the sensitive detection of Pb(II) and Cd(II) by square-wave anodic stripping voltammetry (SWASV). The as-synthesized nanocomposites were characterized by energy-dispersive spectroscopy (EDS), Raman spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). (BiO)CO composite plays a key role in the improvement of the detection sensitivity, which can form multicomponent alloy with cadmium and lead. Additionally, the unique structure of rGO can enlarge the surface area and provide abundant active sites. Moreover, Nafion incorporation in the nanocomposite can effectively increase the adhesion and mechanical strength of the film, and further improve the preconcetration ability due to the cation-exchange capacity of its abundant sulfonate groups. As expected, the (BiO)CO-rGO/Nafion nanocomposite-modified glassy carbon electrode ((BiO)CO-rGO-Nafion/GCE) achieved low detection limits of 0.24 μg/L for Pb(II) and 0.16 μg/L for Cd(II), in the linear range of 1.0-60 μg/L, and showed some excellent performance, such as high stability, good selectivity, and sensitivity. Finally, synthetic water samples were prepared and further used to verify the practicability of the (BiO)CO-rGO-Nafion/GCE with satisfactory results.
本文合成了碳酸氧铋（BiO）CO-还原氧化石墨烯纳米复合材料，并将其进一步应用于 Nafion 基质中（（BiO）CO-rGO-Nafion），首次通过方波阳极溶出伏安法（SWASV）灵敏检测 Pb(II) 和 Cd(II)。通过能量色散光谱（EDS）、拉曼光谱、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、X 射线衍射（XRD）、循环伏安法（CV）和电化学阻抗谱（EIS）对合成的纳米复合材料进行了表征。（BiO）CO 复合材料在提高检测灵敏度方面起着关键作用，它可以与镉和铅形成多组分合金。此外，rGO 的独特结构可以增大表面积并提供丰富的活性位点。此外，纳米复合材料中 Nafion 的掺入可以有效增加薄膜的附着力和机械强度，并由于其丰富的磺酸盐基团的阳离子交换能力进一步提高预浓缩能力。不出所料，（BiO）CO-rGO/Nafion 纳米复合材料修饰玻碳电极（（BiO）CO-rGO-Nafion/GCE）对 Pb(II) 的检测限低至 0.24 μg/L，对 Cd(II) 的检测限低至 0.16 μg/L，线性范围为 1.0-60 μg/L，表现出一些优异的性能，如高稳定性、良好的选择性和灵敏度。最后，制备了合成水样，并进一步使用（BiO）CO-rGO-Nafion/GCE 验证了其实用性，结果令人满意。
