Nano Biochip Research Group, Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis (UniMAP), Kangar, Perlis 01000, Malaysia.
Nanoscale Res Lett. 2013 Feb 11;8(1):68. doi: 10.1186/1556-276X-8-68.
ZnO nanorods were synthesized using a low-cost sol-gel spin coating technique. The synthesized nanorods were consisted of hexagonal phase having c-axis orientation. SEM images reflected perpendicular ZnO nanorods forming bridging network in some areas. The impact of different hydrogen concentrations on the Pd-sensitized ZnO nanorods was investigated using an impedance spectroscopy (IS). The grain boundary resistance (Rgb) significantly contributed to the sensing properties of hydrogen gas. The boundary resistance was decreased from 11.95 to 3.765 kΩ when the hydrogen concentration was increased from 40 to 360 ppm. IS gain curve showed a gain of 6.5 for 360 ppm of hydrogen at room temperature. Nyquist plot showed reduction in real part of impedance at low frequencies on exposure to different concentrations of hydrogen. Circuit equivalency was investigated by placing capacitors and resistors to identify the conduction mechanism according to complex impedance Nyquist plot. Variations in nanorod resistance and capacitance in response to the introduction of various concentrations of hydrogen gas were obtained from the alternating current impedance spectra.
采用低成本的溶胶-凝胶旋涂技术合成了氧化锌纳米棒。所合成的纳米棒由具有 c 轴取向的六方相组成。SEM 图像反映了在某些区域中垂直的 ZnO 纳米棒形成桥接网络。使用阻抗谱（IS）研究了不同氢浓度对 Pd 敏化 ZnO 纳米棒的影响。晶界电阻（Rgb）对氢气的传感性能有显著贡献。当氢浓度从 40 增加到 360 ppm 时，边界电阻从 11.95 减小到 3.765 kΩ。IS 增益曲线显示在室温下，360 ppm 氢气的增益为 6.5。奈奎斯特图显示在暴露于不同浓度的氢气时，低频处的阻抗实部减小。通过放置电容器和电阻器来研究电路等效性，根据复阻抗奈奎斯特图确定传导机制。从交流阻抗谱中获得了纳米棒电阻和电容对引入各种浓度氢气的响应变化。
