NANOSIZED ZINC OXIDE DEPOSITED ON SINGLE WALL CARBON NANOTUBES COMPOSITES FOR NITROGEN DIOXIDE-SENSOR IN MUSEUMS AND ART GALLERIES MONITORING

The aim of this investigation is to develop a material and technique for detects the smallest traces of poison gases and for the instantaneous rate of atmospheric corrosion of archaeological materials indoor. This paper describes the development and use of a single walled carbon nanotubes with ZnO (SWCNT/ZnO) composites as a Networks to investigate it as resistive gas sensors for NO2 detection. Sensor film was coated on an sapphire substrate by spin coater. At room temperature, SWCNT/ZnO composites with equal weight ratio have shown quite high sensitivity to NO2 concentrations as low as 1 ppm, this gives the opportunity to us it as a sensor to control the environment of the places where the cultural heritage materials are found. All ZnO (SWCNT/ZnO) tested sensors exhibit high stability and relatively low response and recovery time. The highest response values of the composite were achieved at temperatures ranging between 100 and 300°C and gas concentrations higher that 50 ppm. For all gas concentrations, the SWCNT/ZnO sensor shows much impressive performance at temperatures higher than 100°C compared to pure SWCNT sensor. The results show that this type of material is surprising, revealed that the measured sensitivity upon exposure to NO2 strongly depends on the changing matrix of the microstructure and the preparation conditions of the composite material. The gas detection mechanisms as well as the optimal gas sensing parameters were discussed