Bismuth Subcarbonate Decorated Reduced Graphene Oxide Nanocomposite for the Sensitive Stripping Voltammetry Analysis of Pb(II) and Cd(II) in Water

Abstract

In this paper, bismuth subcarbonate (BiO)2CO3-reduced graphene oxide nanocomposite incorporated in Nafion matrix ((BiO)2CO3-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)2CO3 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)2CO3-rGO/Nafion nanocomposite-modified glassy carbon electrode ((BiO)2CO3-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)2CO3-rGO-Nafion/GCE with satisfactory results.

Linker-Free Magnetite-Decorated Gold Nanoparticles (Fe3O4-Au): Synthesis, Characterization, and Application for Electrochemical Detection of Arsenic (III)

“…EIS was used to explore the material/electrode interface properties and changes based on the impedance changes ( Figure S2B ). The EIS results show different semicircles, each with a diameter equivalent to the charge transfer resistance (R ct ), which corresponds to the process of electron transfer limitation [ 47 , 48 , 49 ]. Based on the value of semicircle diameter, the order of the R ct of different modified electrodes was as follows: Fe 3 O 4 /GCE (curve b) > Fe 3 O 4 -Au/GCE (curve c) > Fe 3 O 4 -Au-IL/GCE > bare GCE (curve a).…”

Multiplexed Anodic Stripping Voltammetry Detection of Heavy Metals in Water Using Nanocomposites Modified Screen-Printed Electrodes Integrated With a 3D-Printed Flow Cell

“…The (BiO) 2 CO 3 -rGO-Nafion and Fe 3 O 4 -Au-IL sensing nanocomposites were synthesized based on previously reported protocols ( Zhao et al, 2020 ; Sedki et al, 2021 ) using the following steps.…”

“…The employment of the disposable SPEs avoided the traditional pretreatment process frequently-used to prepare glassy carbon or carbon paste WE, but obtained a comparable sensitivity based on the modification of the nanocomposites. Compared to the batch electrochemical cells in previously published papers, including ours (Zhao et al, 2020;Sedki et al, 2021), the flow electrochemical stripping analysis reported in this study has the advantages of: automation potential, high throughput analysis of large quantities of samples, high reliability due to reduced human intervention, miniaturization potential on the size of analytical cell/device, near-/real-time detection, integration with other analytical systems and capability for the simultaneous detection of As(III), Cd(II), and Pb(II). Additionally, the flow cell geometry was optimized and finally confirmed by COMSOL Multiphysics to resolve the problems existing in the application of SPEs in flow system based on a finite element method (FEM), which is a reliable and effective approach for the computational fluid dynamic (CFD) analysis.…”

“…Nano-materials/composites modified electrodes for detection of heavy metals Pb(II), Cd(II), and As(III) in water by ASV in batch electrochemical cells has received a great deal of attention ( Bi et al, 2010 ; Pandey et al, 2016 ; Zhao et al, 2020 ; Sedki et al, 2021 ). While highly sensitive and selective, batch cells have limitations.…”

“…The SPEs were composed of two WEs, a CE and a Ag/AgCl quasi-RE. As well, two sensing nanocomposites, i.e., (BiO) 2 CO 3 -reduced graphene oxide (rGO)-Nafion ((BiO) 2 CO 3 -rGO-Nafion) and Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 MNPs) @Au nanoparticles (AuNPs)-ionic liquid (IL) (Fe 3 O 4 -Au-IL), with different catalytic properties were used to modify the two WEs integrated in SPE separately based on our previous works ( Zhao et al, 2020 ; Sedki et al, 2021 ) with small changes to obtain a good sensitivity and selectivity, as compared with the bare SPEs. On this basis, a homemade flow system for the stripping voltammetry analysis of HMIs was developed, comprising a nanocomposites-modified SPE integrated with an 3D-printed flow cell.…”