Arrays of copper nanowire electrodes: Preparation, characterization and application as nitrate sensor

Abstract

a b s t r a c tEnsembles of copper nanowire electrodes (CuWNEEs) are prepared via electrodeposition in track-etched polycarbonate membranes. Three different preparation methods are compared showing that the better results in terms of sensor durability and reproducibility are achieved by pre-sputtering a thin gold film on the templating membrane and attaching it to a supporting electrode by exploiting the adhesion property and ionic conductivity of a thin Nafion interlayer. SEM-EDS analyses together with double layer charging currents measurements indicate that these arrays are formed by copper nanowires with 400 nm diameter, 10 m length distributed with a spatial density of 1 × 10 8 nanowires/cm 2 . The voltammetric reduction of nitrate at CuWNEEs is characterized by a well-resolved cathodic peak at approximately −0.680 V vs Ag/AgCl, whose current scales linearly with the nitrate concentration in the 10-400 M range. The limit of detection (LOD) achieved by simple linear sweep voltammetry is in the 1.7-3.0 M range, depending on the CuWNEE preparation method, such LOD values being among the lowest reported up to now in the literature. The possibility to use CuWNEEs in chloride and nitrite containing water samples is demonstrated.

Fabrication and Characterization of a Cu-Zn-TiO2Nanotube Array Polymetallic Nanoelectrode for Electrochemically Removing Nitrate from Groundwater

“…In a previous study, a Zn cathode was found to have a higher electrocatalytic activity for the reduction of NO 3 − than did other cathodes. Keita found that adding Zn 2+ to the electrolyte positively affected cathodic reduction of NO 2 − , indicating that Zn is a suitable complementary cathode metal to Cu in terms of reaction kinetics. Cu catalyzed the reduction of NO 3 − to NO 2 − and Zn catalyzed the reduction of NO 2 − to the final product.…”

Techniques in Advancing the Capabilities of Various Nitrate Detection Methods: A Review

“…Table 5 summarises the main advantages and disadvantages of electrochemical systems. [29,30,56,66,68,72] * Less power consumption during operation [28,30] * Simple operation for direct determination of nitrate [29,30,68] *High selectivity towards targeted ions [30,56] *Fast response/feedback system [66,67] *Suitable for in situ/on line analyses [30,66] *Viable approach for portable application as relatively simple [30,56] *Low-cost system [56,68] *Small and compact system [29,30] *Surface cumulative passivation effect [28] *Complicated programmed potential protocol for renewal of microelectrode surface/electrode reactivation [28] *Extensive procedure for reagent preparation [27] *Measurement result is influenced by other contamination in analyte solution/samples [26] *Tedious reagent preparation procedure [27] *Sensitive materials such as dope polypyrrole need to be stored in the dark during polymerisation [26,29] *Sensitive materials such as dope polypyrrole are expensive [29,30] *Sensitive materials such as nitrate reductase enzymes are too sophisticated to be field-deployable [29,30] *Interference of other ions in water such as chloride, sulphate and phosphate [26] *Requirement of different types of material for the electrode in the system such as working, counter and reference electrode [27,…”

The Roles of Hydrazine and Ethylenediamine in Wet Synthesis of Cu Nanowire

“…Many authors have studied different kinds methods to synthesize copper nanowires, including synthesis using template materials [1][2][3][4][5][6], solvothermal or hydrothermal [7,8], and wet synthesis [9][10][11][12][13]. Although the template technique produces a quite clean and straight copper nanowires, but the process requires cleaning the sacrificed materials which considered as a delicate and time-consuming process.…”

“…Although the template technique produces a quite clean and straight copper nanowires, but the process requires cleaning the sacrificed materials which considered as a delicate and time-consuming process. The solvothermal and template technique might produce a long nanowire ranging about hundred nanometers in diameter with ten micrometers in length [1][2][3][4][5][6][7][8], but the process usually took a number of hours. And therefore, it is considered as time-consuming.…”