Mesoporous tin oxide nanospheres for a NOx in air sensor

Mesoporous tin oxide (SnO2) with a high surface area of 147.5 m(2)/g has been successfully synthesized via self-assembly process, combining the driven forces of water-evaporation and molecular interactions. Scanning electron microscope, X-ray diffraction, transmission electron micrograph, Fourier transform infrared and BrunauerEmmett- Teller were employed to analyze the morphology and crystal structure of the as-synthesized mesoporous materials. As a gas sensor, mesoporous SnO2 shows impressive performances towards NOx gas with high selectivity and stability as well as ultra high sensitivity about 94.3 to 10 ppm NOx gas at 300 degrees C. The best response time of the sample S-500 is about 3.4 s to 10 ppm NOx at 450 degrees C.