화학공학소재연구정보센터
Materials Chemistry and Physics, Vol.119, No.3, 424-427, 2010
Fabrication of nanotubules of thermoelectric gamma-Na0.7CoO2 using porous aluminum oxide membrane as supporting template
We report the successful synthesis of nanotubules of thermoelectric materials gamma-NaxCoO2 using two different sol-gel routes aided by porous anodized aluminium oxide (AAO) membrane as supporting templates. The gamma-NaxCoO2 nanotubule using urea-based route can be achieved at 650 degrees C at a heating rate of 1 degrees C min(-1) and held for 4 h. The gamma-NaxCoO2 nanotubule using citric acid-based route can be achieved at 500 degrees C using a rapid-heat-up procedure and held for 30 min. The products were investigated using various techniques including XRD, SEM and TEM. Electron diffraction pattern taken along [0 0 1] zone axis direction on the nanotubule shows that all the diffraction spots can be indexed using a hexagonal unit cell with a = b = 0.56 nm, which can be considered as a superstructure with cell doubling within the ab plane. (C) 2009 Elsevier B.V. All rights reserved.