One-Step Electrochemical Deposition of Reduced Graphene Oxide-Bismuth Nanocomposites for Determination of Lead

Abstract

The novel reduced graphene oxide-bismuth (RGO-Bi) nanocomposites were successfully synthesized through one-step electrochemical reduced deposition and used to modify disposable screen-printed electrode (SPE) for determination of Pb(II). By electrochemical deposition, a large number of Bi particles were distributed on RGO. Combined the unique structure and electronic properties of RGO with the ability of Bi to form alloys with other metals, the RGO-Bi/SPE has shown wide linear range and low detection limit for determination of Pb(II). Additionally, the RGO-Bi/SPE was successfully applied to the rapid determination of Pb (II) Heavy metal pollution is becoming more and more serious in the coastal zone environment.1 Electrochemical techniques are widely used in the determination of metal ions owing to the advantages of low cost, high sensitivity, and great convenience in operation, etc. Recently, various bismuth-based electrodes have been extensively used for heavy metals detection through anodic stripping voltammetry (ASV) instead of mercury-based electrodes 3-5 owing to the low toxicity, wide potential window, and insensitivity to dissolved oxygen, ect.6,7 Reduced graphene oxide (RGO) is a new carbon nanomaterial, which has been widely used for its unique structure and electronic properties.8-11 Many bismuth-based electrodes modified with nanomaterials, 8,[12][13][14][15][16][17] such as carbon nanotube, graphene, etc., have been reported for the determination of heavy metals.In this paper, we report a new method to fabricate a RGO-Bi nanocomposite modified SPE (RGO-Bi/SPE) by one-step electrochemical deposition. Pb(II) was used as a model to be detected at RGO-Bi/SPE because Pb(II) is one of the major pollutants in both terrestrial and aquatic ecosystems. 18,19 The linear response was in the concentration range of 0.05-20 μM with a detection limit of 6.8 nM in the optimized situation. The repeatability of the RGO-Bi/SPE was also excellent with the RSD of 4.6%. ExperimentalMaterials and instruments.-All chemicals and reagents were of analytical grade. The morphologies of modified electrodes were characterized by scanning electron microscopy (SEM Hitachi S-4800). Inductively coupled plasma-mass spectrometry (ICP-MS, ELAN DRC) was used for comparative testing. Electrochemical Work Station (CHI 660D) was used throughout all electrochemical experiments. SPE which includes a screen-printed carbon working electrode (3 mm in diameter), carbon auxiliary electrode and a silver chloride reference electrode were purchased from Taiwan Chanpu Science and Technology Company.Preparation of the RGO-Bi/SPE electrode.-Prior to use, SPE was rinsed and ultrasonicated with deionized water and then subjected to potential cycling (−0.6∼0.6 V, 10 mV/s) in 0.5 M H 2 SO 4 . Bi(III) solution (120 mg/L) was mixed with the prepared GO (1.0 mg/mL) dispersion in volume ratio of 1:2 and ultrasonicated for 1 min. Subsequently, 5 μL mixed GO-Bi(III) suspensions were dropped on the surface of SPE and dried using an infrared lamp. Then the modifie...

Preparation of bismuth-based microrods and their application in electroanalysis

“…Two asymmetrical main peaks observed at 159.42 and 164.76 eV in Fig. 2b correspond to the Bi 4f7/2 and 4f5/2 signals, respectively [10]. These peaks implied that the bismuth was present in the Bi 3+ oxidation state, consistent with previous findings.…”

“…Especially when underlying electrode substrate exhibits fast electron transfers kinetics, the improvements of using BiFE modified electrode were not apparent and in some cases can lead to a detrimental effect upon the electroanalytical response [7]. Then other forms of bismuth, such as bismuth nanoparticles, bismuth nanosheets were reported as modified materials in electroanalysis [10,11], and the change of the morphology improved those materials' stabilities to some extent. Besides, bismuth oxide modified carbon electrode [12] and screen printed electrode [13] had also been employed for the determination of heavy metal ions due to its characteristic parameters such as the energy band gap, and photoconductivity.…”

Screen-Printed Electrodes Modified with “Green” Metals for Electrochemical Stripping Analysis of Toxic Elements

“…Apart from bulk Bi electroplating from a solution containing Bi(III) (either in situ or ex situ), some approaches utilize a Bi(III) salt placed on the surface SPE; reduction of Bi(III) in situ results in the formation of a Bi film. As an example, a reduced graphene oxide/Bi-modified SPE has been developed by drop casting a Bi(III)/GO mixture of the surface of the electrode and electroreduction of Bi(III) [ 55 ].…”

Stripping Voltammetric Determination of Lead in Coastal Waters With a Functional Micro-Needle Electrode

“…Many techniques have been developed for the determination of heavy metal ions, including atomic absorption spectroscopy, atomic emission spectroscopy, and inductively coupled plasma-mass spectrometry (Manivannan and Biju, 2011;Zhu et al, 2017). Although these methods possess various advantages and have been commonly used, the requirement of cumbersome instruments, time-consuming pretreatments, and high cost are the inevitable limitations (Hu et al, 2015;Zhang et al, 2016).…”