Goyal Rajendra N, Pandey Ashish K, Kaur Davinder, Kumar Ashvani
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India.
J Nanosci Nanotechnol. 2009 Aug;9(8):4692-9. doi: 10.1166/jnn.2009.1278.
In the present study, Fe2O3 nanopowder has been grown by Ultrasonic mist chemical vapor deposition (UM-CVD), which is a promising method for large area deposition at low temperatures taking in to account of its simplicity, inexpensiveness and safety. Room temperature XRD results revealed prominent hematite phase with intense (104) reflection and was also in agreement with the HR-TEM results. In situ high temperature X-ray diffraction (XRD) studies clearly indicated the change of phase from hematite to magnetite as the temperature increases above 300 degrees C. The surface morphology and particle size distribution of Fe2O3 nanopowder were characterized using field emission scanning electron microscope (FE-SEM) and high resolution transmission electron microscope (HR-TEM), which revealed that the particles were spherical in nature and distributed in range of 50-100 nm. SQUID magnetometry results indicate the ferromagnetic nature of the nanopowder with crystallite size of 6 nm as calculated from M-H curve. Transmittance of approximately 55% and estimated direct band gap of 2.5 eV was observed. Further, the nanopowder was used to modify glassy carbon electrode (GCE) and the modified electrode was found to exhibit electrocatalytic activity for the oxidation of dopamine. It is expected that the nanopowder will exhibit promising applications in the development of sensors.
在本研究中，通过超声雾化化学气相沉积（UM-CVD）法制备了Fe2O3纳米粉末。考虑到其简单性、低成本和安全性，这是一种在低温下进行大面积沉积的有前景的方法。室温XRD结果显示出具有强烈（104）反射的显著赤铁矿相，这也与高分辨透射电子显微镜（HR-TEM）结果一致。原位高温X射线衍射（XRD）研究清楚地表明，当温度升高到300℃以上时，相从赤铁矿转变为磁铁矿。使用场发射扫描电子显微镜（FE-SEM）和高分辨透射电子显微镜（HR-TEM）对Fe2O3纳米粉末的表面形貌和粒径分布进行了表征，结果表明颗粒呈球形，粒径分布在50-100nm范围内。超导量子干涉仪（SQUID）磁强计结果表明，根据M-H曲线计算，纳米粉末具有铁磁性，微晶尺寸为6nm。观察到透过率约为55%，估计直接带隙为2.5eV。此外，该纳米粉末用于修饰玻碳电极（GCE），发现修饰电极对多巴胺的氧化具有电催化活性。预计该纳米粉末在传感器开发中将展现出广阔的应用前景。
