Fabrication of Bismuth/Multi‐walled Carbon Nanotube Composite Modified Glassy Carbon Electrode for Determination of Cobalt

Abstract

A bismuth/multi-walled carbon nanotube (Bi/MWNT) composite modified electrode for determination of cobalt by differential pulse adsorptive cathodic stripping voltammetry is described. The electrode is fabricated by potentiostatic pre-plating bismuth film on an MWNT modified glassy carbon (GC) electrode. The Bi/MWNT composite modified electrode exhibits enhanced sensitivity for cobalt detection as compared with the bare GC, MWNT modified and bismuth film electrodes. Numerous key experimental parameters have been examined for optimum analytical performance of the proposed electrode. With an adsorptive accumulation of the Co(II)-dimethylglyoxime complex at -0.8 V for 200 s, the reduction peak current is proportional to the concentration of cobalt in the range of 4.0×10-10 -1.0×10 -7 mol/L with a lower detection limit of 8.1×10 -11 mol/L. The proposed method has been applied successfully to cobalt determination in seawater and lake water samples.

Trace level voltammetric determination of lead and cadmium in sediment pore water by a bismuth-oxychloride particle-multiwalled carbon nanotube composite modified glassy carbon electrode

“…It is well-known that bismuth-modified carbon nanotube-based electrodes are excellent with respect to electrochemical detection of ultratrace metals [45][46][47][48][49][50][51][52]. Also, it is known that the combining MWCNTs with Bi 2 O 3 gives rise to composites appropriate as the modifiers of choice for the determination of H 2 O 2 [44], anticoagulant acenocoumarole [53] and antidepressant drug escitalopram [54], as well.…”

“…Different designs were elaborated to improve the adhesion of bismuth particles onto / into the substrate, especially those based on carbonaceous materials, which expands the applicability of the respective electrodes at various pH, or to enhance the stability, sensitivity and/or selectivity of the electrode surface [40][41][42][43][44][45][46][47][48][49][50][51][52]. There were numerous efforts to improve the sensitivity of bismuth-based working electrodes, including the expansion of the sensor surface via the synthesis of mesoporous bismuthbased materials [41,42], the enlargement of the substrate electrode surface before modification with bismuth [43] and the incorporation of micro/nanoparticles of bismuth or bismuth-composite nanoparticles [20,[44][45][46][47][48][49][50][51][52][53].…”

“…There were numerous efforts to improve the sensitivity of bismuth-based working electrodes, including the expansion of the sensor surface via the synthesis of mesoporous bismuthbased materials [41,42], the enlargement of the substrate electrode surface before modification with bismuth [43] and the incorporation of micro/nanoparticles of bismuth or bismuth-composite nanoparticles [20,[44][45][46][47][48][49][50][51][52][53]. Nafion s protective layers [15,20,21,[23][24][25]27,48,51], or other compounds like surfactants [15,21] or complex-forming agents (e.g.…”

Sensitive Voltammetric Detection of Trace Heavy Metals in Real Water Using Multi-Wall Carbon Nanotubes/Nafion Composite Film Electrode

“…[8][9][10] However, because of the toxicity of mercury, future regulations and occupational health considerations may severely restrict (or ban) the use of mercury as an electrode material. 11,12 New alternative electrode materials were highly desired to develop "environmentally friendly" stripping sensors for meeting the growing demands for on-site environmental monitoring of trace metals.…”

Thick-film carbon-containing electrodes modified with multi-walled carbon nanotubes in adsorptive stripping voltammetry of iron(III)

“…The simplicity of voltammetric measurements, low detection limits of elements being determined, short analysis time, reliability, and small size and low cost of the equipment allow stripping voltammetry (SV) to compete with other highsensitivity methods (e.g., atomic absorption spectroscopy, mass spectrometry, chromatography, etc.) in analysis of water, soil, foodstuffs, and various biological materials for the determination of heavy metal traces [2].The use of CNT for enhancing the sensitivity of glassy carbon, carbon paste, and impregnated electrodes to metal ions in methods of anodic [3-9], cathodic [10], and adsorptive stripping voltammetry (AdSV) [11][12][13][14][15][16][17] has been reported. However, these solid-phase sensors are expensive and require manual mechanical treatment of the surface between the measurements, so that the analysis results become fully dependent on the analyst skill.…”