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Co3O4 Nanostructures with Different Morphologies and their Field‐Emission Properties |
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| Authors: | B Varghese C H Teo Y Zhu M V Reddy B V R Chowdari A T S Wee V B C Tan C T Lim C‐H Sow |
| Affiliation: | 1. National University of Singapore Nanoscience and Nanotechnology Initiative (NUSNNI), 2 Science Drive 3, Singapore 117542 (Singapore);2. Department of Physics, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore);3. Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore);4. Division of Bioengineering, National University of Singapore, Blk E3A, 9 Engineering Drive 1, Singapore 117576 (Singapore) |
| Abstract: | We report an efficient method to synthesize vertically aligned Co3O4 nanostructures on the surface of cobalt foils. This synthesis is accomplished by simply heating the cobalt foils in the presence of oxygen gas. The resultant morphologies of the nanostructures can be tailored to be either one‐dimensional nanowires or two‐dimensional nanowalls by controlling the reactivity and the diffusion rate of the oxygen species during the growth process. A possible growth mechanism governing the formation of such nanostructures is discussed. The field‐emission properties of the as‐synthesized nanostructures are investigated in detail. The turn‐on field was determined to be 6.4 and 7.7 V μm–1 for nanowires and nanowalls, respectively. The nanowire samples show superior field‐emission characteristics with a lower turn‐on field and higher current density because of their sharp tip geometry and high aspect ratio. |
| Keywords: | Cobalt oxides Field emission Nanostructures inorganic Nanowires inorganic |