Fabrication of new C/ZnO/ZnO composite material and their enhanced gas sensing properties

In this present work, we report the fabrication of a new type carbon fiber mixed mesporous composite C/ZnO/ZnO materials by hydrothermal method and their characterization. urchin-liked ZnO particles and chopped C fiber formed excellent and contacted by nano rod-liked ZnO coating around C fiber surface. The specific surface area of pure urchin-liked ZnO is larger than that of C fiber with ZnO coating. Gas sensing tests of new sensors were performed to ammonia, methane, ethanol and acetone. The results show that, with C fiber content increasing from 3 to 10 wt%, response values of C/ZnO/ZnO sensors increase evidently. Especially in 300 ppm ethanol, the highest response value is 36.44, while that of pure ZnO sensor is 23.64. Furthermore, it is observed that the sensor with 10 wt% C fiber content exhibits favorable selectivity to ethanol at 250-300 ℃, and superior repeatability and long term stability as well.