Nitrate detection activity of Cu particles deposited on pencil graphite by fast scan cyclic voltammetry

Abstract

Electrocatalytic nitrate reduction and sensing activities of Cu deposits from 0.01 M CuSO4· 5H2O solution by fast scan (1000 mV/s) cyclic voltammetry on pencil graphite (PG) was investigated. The content of Cu particles on PG surface was controlled by fixing the deposition cycles between 0 and −300 mV. The performance of the different Cu/PG electrodes has been explained in terms of reduction current, kinetic order, exchange current density, specific electrical capacitance and nitrate sensing abilities. All these activities were modestly dependent on the content of Cu particles on the PG surface. The minimum catalytic sites on PG surface were generated even by the single Cu deposition cycle. Depending on the Cu content, the electrodes exhibited lowest nitrate detection limits in the range between 1.0 × 10−4to 1.1 × 10−3M. The nitrate detection performance of the Cu/PG electrode was justified with the ion chromatographic method.