SnO2 nanoparticle-coated In2O3 nanofibers with improved NH3 sensing properties

SnO2 nanoparticles and In2O3 nanofibers are synthesized via a sol–gel process and an electrospinning method, respectively. Excellent sensing materials for NH3 detection are achieved by coating SnO2 nanoparticles on In2O3 nanofibers. When the as-prepared sensors were exposed to 1 ppm NH3 at room temperature, the response is 21, and the response and recovery times are 7 and 10 s, respectively. With this method, NH3 can be detected down to a concentration of 0.1 ppm, and the corresponding response is about 2. The selectivity and stability of the sensors are satisfactory for gas sensing. And the surface coating is proved to be an effective method for the sensing enhancement of one-dimensional nanomaterials.