Plasma Deposited Metal-Oxide Nanosensors for Amine Detection

Abstract

The metal-oxides have raised significant scientific interest in recent years, due to their sensing properties. In is notable that the gas sensing properties can be enhanced by structural and morphological manipulation of the sensor. Previously was demonstrated that increasing the sensor surface to volume ratio during synthesis with formation of sheet-like structures or nanowires can enhance the sensor sensitivity [1,2]. Among different oxides, cuprous oxide is interesting due to its wide band gap and stability [3]. Cuprous oxide nanostructures can be synthesized by different methods ranging from solution based chemical methods to thermal and plasma synthesis [4]. However one of most optimal in terms of time, simplicity and quality of synthesized nanostructures is plasma processing, especially at atmospheric pressures. For this reason, the atmospheric DC plasma source was used for deposition of CuO nano-sheets on the surface of copper electrodes [5,6]. The prepared samples were then used to detect different amines (diethylamine, trietylamine, cyclohexanamine) which are present in vapours generated in spoiled food and many industrial processes. These chemical substances are cancerogenious and represent serious health hazards to humans. The developed gas-vapour sensor exhibited an excellent resistive sensitivity for these chemicals even at temperatures below 100 °C. In performed evaluation analysis, the morphology of the CuO nanostructures was changed, but results demonstrated that sensitivity is preserved during morphological changes as long as crystallinity remains similar, and the sensor material is of nanosize-dimension at least in one direction. The obtained results were explained by theoretical investigation of sensor performance. [1] S. Steinhauer et al., Sensors and Actuators B: Chemical, 187 (2013), 50-57 [2] C. Yang et al., Sensors and Actuators B: Chemical, 207 (2015), 177-185 [3] M. Hübner et al., Sensors and Actuators B: Chemical, 153 (2011), 347-353 [4] G. Filipič et al., Nanotechnology, 23 (2012), 194001 [5] J. Gruenwald et al., Plasma Processes and Polymers, 13 (2016), 946-954. [6 ] J. Gruenwald et al., Plasma Processes and Polymers, 13 (2016), 766-774