Detection of chromium(VI) in water using an electrochemical sensor based on ketjen black-modified carbon cloth

A CB/CCE electrochemical sensor for Cr(VI) detection was prepared by ultrasonic dispersion of Ketjen Black and then the coating of modified carbon cloth electrode. Material morphology and composition were characterized based on XPS, TEM, BET, BJH; electrochemical performance of the electrode was studied based on LSV, EIS and CV. The results show that the high conductivity of Ketjen Black accelerates charge transfer on the electrode surface, while the abundant mesoporous structure and large specific surface area enhance Cr(VI) adsorption and reduction by the electrode. Under the optimal experimental conditions, the relationship between the reduction peak current of Cr(VI) and its concentration in the sample was studied by the i-t method. The reduction peak current intensity and its concentration demonstrate a good linear relationship in the range of 0.025-57μM and 57-483μM. The linear equations are: Ip(µA) = -0.2452C(µM)-0.0303 (R = 0.9908), Ip(µA) = -0.0329C(µM)-15.9212 (R = 0.9853), LOD is 9.88nM (S/N = 3). Compared with other methods, the sensor displays outstanding detection performance advantages. Plus the advantages of low cost and environmental protection, it has good application prospects in detecting Cr(VI) in water. © 2021 Technoscience Publications. All rights reserved.