Enhanced acetone sensing properties based on in-situ growth SnO2 nanotube arrays.

Large-scale and well-aligned in-situ growth SnO2 nanotube arrays have been synthesized on the surface of the Al2O3 ceramic tube by a cost-effective template self-etching method. The morphology of in-situ SnO2 nanotubes can be adjusted by changing the concentration of urea. The structure and morphology characteristics of SnO2 nanotube were examined via X-ray diffraction, BET, and scanning electron microscopy, respectively. Combining the advantages of unique hollow structure and favorable orientation growth, the in-situ SnO2 nanotube arrays were utilized in the fabrication of gas-sensing devices. A series of detections were carried out to evaluate the gas sensing performances. The in-situ growth SnO2 nanotube arrays sensor exhibited a higher acetone sensing performance, compared with the sensors fabricated by a slurry-coating method. The results indicated that in-situ growth SnO2 nanotube arrays sensor exhibited an excellent response (S=20.3), good linearity under the concentration range of ppm level (5-300 ppm), and outstanding selectivity to 100 ppm of acetone gas. Furthermore, the dominant sensing mechanism about the in-situ growth SnO2 nanotube arrays sensor has been discussed in detail.