Enhanced acetone sensing properties based onin situgrowth SnO₂nanotube arrays

Large-scale and well-alignedin situgrowth SnO₂nanotube (NT) arrays have been synthesized directly on the surface of the Al₂O₃ceramic tube by a cost-effective template self-etching method. The morphology ofin situSnO₂NTs can be adjusted by changing the concentration of urea. The structure and morphology characteristics of SnO₂NT were examined via x-ray diffraction, BET, and scanning electron microscopy, respectively. A series of detections were carried out to evaluate the gas sensing performances. The results indicated thatin situgrowth SnO₂NT 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. Compared with the sensors fabricated by a slurry-coating method, the controllablein situassembled SnO₂NT arrays exhibited a more stable structure and easier fabrication process. The high acetone sensing performance might due to the unique hollow structure and favorable orientation growth. The dominant sensing mechanism about thein situgrowth SnO₂NT arrays sensor has been discussed in detail. It is expected thatin situgrowth SnO₂NT arrays sensor with the general working principle and controllable growth strategy will become a promising functional material in monitoring and detecting acetone.