Fabrication and NO2 gas sensing performance of TeO2-core/CuO-shell heterostructure nanorod sensors

• Published in: Nanoscale research letters 2014-11, Vol.9 (1), p.638-638, Article 638
• Main Authors: Park, Sunghoon, Kim, Soohyun, Sun, Gun-Joo, In Lee, Wan, Kim, Kyoung Kook, Lee, Chongmu
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Materials Science; Molecular Medicine; Nano Express; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering
• ISSN: 1931-7573; 1556-276X; 1556-276X
• DOI: 10.1186/1556-276X-9-638

TeO 2 -nanostructured sensors are seldom reported compared to other metal oxide semiconductor materials such as ZnO, In 2 O 3 , TiO 2 , Ga 2 O 3 , etc. TeO 2 /CuO core-shell nanorods were fabricated by thermal evaporation of Te powder followed by sputter deposition of CuO. Scanning electron microscopy and X-ray diffraction showed that each nanorod consisted of a single crystal TeO 2 core and a polycrystalline CuO shell with a thickness of approximately 7 nm. The TeO 2 /CuO core-shell one-dimensional (1D) nanostructures exhibited a bamboo leaf-like morphology. The core-shell nanorods were 100 to 300 nm in diameter and up to 30 μm in length. The multiple networked TeO 2 /CuO core-shell nanorod sensor showed responses of 142% to 425% to 0.5- to 10-ppm NO 2 at 150°C. These responses were stronger than or comparable to those of many other metal oxide nanostructures, suggesting that TeO 2 is also a promising sensor material. The responses of the core-shell nanorods were 1.2 to 2.1 times higher than those of pristine TeO 2 nanorods over the same NO 2 concentration range. The underlying mechanism for the enhanced NO 2 sensing properties of the core-shell nanorod sensor can be explained by the potential barrier-controlled carrier transport mechanism. PACS 61.46. + w; 07.07.Df; 73.22.-f