Electrochemical preparation of metallic nano materials and their applications in water analysis

Abstract

A commercially available copper electrical cable and pure Cu disk were used as substrates for the electrodeposition of copper nanoparticles (nano-Cu). The surface morphology of the prepared nano-Cu/Cu electrodes were investigated by scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDX). The bare copper substrates and the nano-copper modified electrodes were utilized and optimized for electrochemical assay of chemical oxygen demand (COD) using glycine as a standard.

A comparison was made among the four types of electrodes (i.e., bare and nano-Cu coated cable and disk) as potential COD sensors. The oxidation behavior of glycine was investigated on the surface of the prepared sensors using linear sweep voltammetry (LSV). Results obtained indicated a significant enhancement of the electrochemical oxidation of glycine at nano-Cu modified electrodes. The effects of different deposition parameters, such as Cu2+ concentration, deposition potential, deposition time, pH, and scan rate on the response of the prepared sensors were investigated. Under optimized conditions, theoptimal nano-Cu based COD sensor exhibited a linear range of 2 to 595 mg/L, and a low limit of detection (LOD) of 1.07 mg/L (S/N = 3).

The developed COD sensors exhibited high tolerance level to Cl- ion where 1.0 M Cl- exhibited minimal interference. The optimized sensors were utilized for the detection of COD in different real water samples and results obtained were validated using the standard dichromate method.