Nitrogen-doped rice grain-shaped titanium dioxide nanostructures by electrospinning: Frequency and temperature dependent conductivity

作者：Babu Veluru Jagadeesh^*; Rao Rayavarapu Prasada; Nair A Sreekumaran; Ramakrishna Seeram

来源：Journal of Applied Physics, 2011, 110(6): 064327.

DOI：10.1063/1.3642979

Rice grain-shaped, nitrogen-doped titanium dioxide (N-TiO2) nanostructures are synthesized using sol-gel method and followed by electrospinning. The as-spun composite fibers are sintered at 500 degrees C for 1 h in air. SEM images of the sintered samples showed rice grain-shaped nanostructures. The nanostructures were made up of spherical nanoparticles with average diameters of similar to 20 nm, and the average diameter decreased with increase of N doping level. The temperature and frequency dependent electrical characterization has carried on nanostructures using impedance spectroscopy in the range of 298 K to 498 K and 30 Hz to 7 MHz, respectively. The magnitude of the ac conductivity is obtained from Nyquist plots and is proved that the ac conductivity is strongly dependent on temperature. The activation energy (E-a) is obtained from Arrhenius plots, and it is lowered from 0.31 to 0.22 eV with increasing N content. Therefore, the rice-grain shaped nanostructures can be employed in the low temperature gas sensor applications.

• 出版日期2011-9-15