Copper oxide synthesis by spray pyrolysis technique: characterizations and application

A. CHETOUI^*1 ,A. ZOUAOUI²

¹Center for Development of Advanced Technologies CDTA, Algiers

²University of Sciences and Technologies Houari Boumediene USTHB, Algiers

^*Corresponding author: A. CHETOUI

ABSTRACT

Spray pyrolysis is a very simple and cost-effectiveness chemical deposition method. Its operating principle is based on the atomizing of a starting solution into fine droplets. The generated droplets are subsequently deposited on substrates carried at high temperatures where the pyrolysis process takes place. Among the advantageous presented by this technique is the possibility of deposition of highly adherent and homogeneous films even on large surfaces [1]. Thus, this processing holds strong promise for employment industrially on large scales. However, in order to get films with the previously mentioned properties, an optimization of the different parameters like the air pressure, the temperature, the nozzle-substrate distance, the nature of the precursor, etc. should be studied in detail.

The spray pyrolysis technique is used to deposit a variety of materials including the semiconductor metallic oxides such as: SnO₂, TiO₂, ZnO, CuO, Cu₂O, NiO, etc [2]. In this work, we are interested in the study of the spray-pyrolyzed copper oxide properties. Copper oxide is a p-type semiconductor which is used in many technological areas such as photocatalysis, super-capacitors, bio-sensors and gas sensors. This work is intended to study the structural, morphological properties and the use of the obtained copper oxide films in gas sensing.

The gas sensor performance is related to three main features: the sensitivity, the selectivity and the stability. We focus here on the enhancement of the sensitivity in terms of the specific surface of detection (SSD). The gas sensitivity is evaluated by measuring the change in one of the electrical properties (current, resistance, capacitance, etc.) of the sensor in the gas atmosphere. It is well known that the sensitivity is as greater as the SSD is large. Hence, we show the different steps which made us able to obtain copper oxide films with a large SSD. As a conclusion, we expose the sensitivity of our sensors towards different CO₂ concentrations.

References

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[2]         F. Paraguay-Delgado, W. AntÌnez-Flores, M. Miki-Yoshida, A. Aguilar-Elguezabal, P. Santiago, R. Diaz, and J. A. Ascencio, "Structural analysis and growing mechanisms for long SnO₂ nanorods synthesized by spray pyrolysis," Nanotechnology, vol. 16, no. 6, pp. 688–694, 2005.