Sea urchin-like SNO_2/Fe_2O_3 microspheres for an ethanol gas sensor with high sensitivity and fast response/recovery

摘要

The sea urchin-like SNO_2/Fe_2O_3 and pure Fe_2O_3 microspheres were fabricated by a simple hydrothermal method. The SEM images show that SNO_2/Fe_2O_3 products are sea urchin-like microspheres which consisted of numerous nanorods. These outward extension nanorods greatly increase the effective contact area between the materials and gas molecules. The results of gas sensing tests indicate the superiority of this material and the enhancement of sensitivity after doping with SNO_2. The SNO_2/Fe_2O_3 sensor response to 100 ppm ethanol at the optimum working temperature of 260 ℃ is 41.7, which is about four times higher than that of pure Fe_2O_3 sensor. Meanwhile the sensors possess ultrafast response and recovery, which are 3 and 4 s respectively.