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Posted: Aug 08, 2012
A new method to produce NO2 nanosensors
(Nanowerk News) Researchers at Materials and Energy Research Centre of Iran in association with Spanish researchers from University of Barcelona succeeded in the synthesis of nanosensors made of indium oxide (In2O3) nanoparticles through a novel alternative current electrophoresis deposition method. This method has better response and shorter time response in comparison with other existing methods (see paper in Sensors and Actuators B: Chemical: "Fabrication of In2O3 based NO2 gas sensor through AC-electrophoretic deposition").
Indium oxide is known as a semiconductor oxide, which is very appropriate for the identification of gases at low temperatures in comparison with other metal oxide semiconductors.
The researchers synthesized various layers of indium oxide (In2O3) nanoparticles through alternative current electrophoresis deposition at various frequencies. Next, they proposed the optimum conditions for the synthesis of such layers by taking into consideration the sensitivity of the layers. A frequency of 10 kHz was reported as the best and the optimum frequency for the synthesis of the sensors.
Then, they produced thick layers of indium oxide nanoparticles by using the optimum frequency in order to compare the properties of the synthesized nanosensor with those of the sensors produced through precipitation method. The comparison proved that the new nanosensor benefited from more functional layers. According to the report of the researchers, the newly synthesized nanosensor provides more space for the passage of the gas due to the presence of pores caused by the chain structure of the interconnected nanoparticles. This fact results in the more desirable response of the nanosensor in comparison with the other sensors.
Studies also showed that the new type of the nanosensor had a quicker response time for the reduction compared to the other type.