Renewable Surface Sol‐gel Derived Carbon Ceramic Electrode Modified with Copper Complex and Its Application as an Amperometric Sensor for Bromate Detection

Abstract

A sol-gel technique was used for the preparation of a three dimensional carbon composite electrode modified with [Cu(bpy) 2 ]Br 2 complex. A reversible redox couple of Cu(II)/Cu(I) is observed at the electrode surface. The electrochemical behavior and stability of the modified electrode was characterized by cyclic voltammetry. The charge transfer coefficient (a) and charge transfer rate constant (K s ) for the modified electrode were determined by cyclic voltammetry, which were found to be 0.46 and 14.2 s À1 , respectively. The modified electrode showed excellent catalytic activity toward bromate reduction at significantly reduced overpotentials and can be used successfully for amperometric detection of bromate. Under the optimized conditions, the calibration plots are linear in the concentration range 0.5 mM À 200mM. Detection limit (signal to noise is 3) and sensitivity were found to be 0.1 mM and 20 nA / mM, respectively. These analytical parameters compare favorably with those obtained with modern analytical techniques. The modified carbon ceramic electrode doped with Cu-Complex shows a good reproducibility, a short response time (t < 2 s), remarkable long term stability (> 4 months) and especially good surface renewability by simple mechanical polishing (RSD for 6 successive polishing is 1.5%).

A new zinc complex of 1-propyl-1H-benzo[d] imidazole: synthesis, characterization and electrocatalysis

“…The detection limit and the sensitivity are 0.05 μM, 67.43 μA μM -1 for trichloroacetic acid detection, and 0.02 μM, 69.94 μA μM -1 for bromate detection. Comparison of performances of different electrochemical sensors for bromate, showed that the detection limit in this study is much lower than earlier reports (0.1 μM [17], 0.036 μM [31] and 0.6 μM [32]) in which other modified electrodes were used, and hence may be suitable for the quantitive analysis of environmentally hazardous materials. The advantages of the bulk-modified Zn-CPE are stability, good catalytic activity, low detection limit and simplicity of preparation.…”

“…When the scan rate was varied from 0.03 to 0.30 V s -1 , the peak potentials changed gradually: the cathodic peak potentials shifted to the negative direction and the corresponding anodic peak potentials shifted to the positive direction with increasing scan rate. The plot of peak current versus scan rate is shown in the inset of electrochemical sensors for bromate, reveal that this detection limit is much lower than earlier reports (0.1 μM [17], 0.036 μM [31] and 0.6 μM [32]) in which other modified electrodes were used.…”

“…Metal complexes are well recognized for their excellent electrocatalytic properties toward the detection of hydrogen peroxide [12][13][14], nitrite [12][13][14][15], bromate [13][14][15] and trichloroacetic acid [16] and so on. The electrochemistry and electrocatalysis of copper complexes with various different ligands have been investigated by several groups [14,15,[17][18][19].…”

Two new copper(II) complexes of 1-Butyl-1H-1,2,4-triazole: synthesis, characterization and electrocatalytic activity

“…9 Recently, great efforts have been directed toward the study of copper(II) complexes incorporating pyridine, thioether, imidazole and imine donors, which not only stem from their fascinating structures but also from their potential applications as new materials. [10][11][12][13] The electrochemical and electrocatalytical properties of copper complexes with various different ligands have been investigated by several groups. 6,7,13,14 Currently, triazoles and their derivatives, known for their rich coordination modes and wide applications as multidentate bridging ligands in coordination chemistry, are of considerable interest.…”

An electrochemical sensing platform based on a new copper complex for the determination of hydrogen peroxide and nitrite

“…Electrochemical reactions catalyzed by metal complexes had attracted considerable attention during the past several decades [12,13]. Recently, considerable efforts have been directed toward the study of Cu(II) complexes incorporating pyridine, thioether, imidazole and imine donors, which not only stem from their fascinating structures but also from their potential applications as new materials [14][15][16][17]. Wang et al studied the electrocatalytic reduction of NO − 2 by copper complexes containing the chelating ligand dipyrido[3,2-d:2 ,3 -f]quinoxaline [18,19].…”