This research work studied Cu electrodeposition over a glassy carbon electrode (GC) using deep eutectic solventes (DESs) instead of conventional aqueous media to subsequently assess the electrodeposit catalytic properties during nitrates reduction. These are nitrogen’s most reduced form, typically present in residual waters from chemical industries, from human consumption and from agriculture, which represent a significant contamination problem; they are not at all easy to eliminate through conventional methods used in water treatment plants, because they can reach potable water sources provoking in humans the incidence of severe illnesses, like cancer among others. It has been shown, that catalysts based in Pd, Pt and Cu metal phases reduce the nitrate ions, where the Cu ones have been studied because of their attractive catalytic properties. There are various forms of synthesizing the Cu catalysts, where electrodeposition leads to better control of Cu nucleation and growth. Cu electrocristalization was carried out from DES to compare the influence of the medium over the nucleation and growth mechanism. The eutectic mixtures used were prepared from choline chloride as the ionic species while the hydrogen bond donnors were urea and ethylene glycol. Both the DES were prepared in a 1:2 molar ratio, taking particular care to establish the influence of the resulting liquid at the early stages of electrodeposition, which was studied from Cu (II) solutions. It was shown that its electrodeposition takes place through a separte stage during which Cu (II) reduces first to Cu (I). All media studied led to demonstrate that electrodeposition follows a nucleation and 3D diffusion controlled growth. The Cu (II) diffusion coefficient, the A (nucleation frequence) and N₀ (number density of active sites) parameters were estimated from potentiostatic plots using the Heerman and Tarallo model. The nitrates reduction at different concentrations was studied via differential pulse voltammetry to determine analytical parameters, like sensibility, detection and quantification limits. The Cu-modified glassy carbon electrodes and a Cu bar served to reduce the nitrates, immersed in 100 mM NaCl supporting electrolyte at pH=1.4 set with HClO₄ analytical grade, adding different KNO₃ concentraciones. It was shown that in acid medium the nitrates ion can be quantified reliably.