Abstract

–The gas-sensing properties of nickel ferrite (NiFe₂O₄) and nickel oxide (NiO) nanoparticles prepared by a self-sustaining levitation-jet synthesis (LJS) method are reported. These have been compared to the gas-sensing properties of a NiO sensor prepared using a commercially sourced powder. The microstructure, surface area, particle size, and morphology varied widely across the sensors fabricated. It was anticipated that these contrasting properties would play a key role in either enhancing or worsening the sensing capabilities of the materials. Gases of interest included ethanol, toluene, and carbon monoxide as well as the gas response of the sensors was investigated at different operating temperatures. In general, the sensors responded to gases with different degrees of sensitivity. Among the sensors with higher surface areas, one provided noticeable enhancements in sensitivity towards gases when compared, for instance, to the sensitivity of the commercially based NiO sensor. The NiFe₂O₄ sensor presented most promise as a gas sensor to ethanol and, to a greater or lesser degree, towards toluene gas. In general, sensors were poorly responsive to the carbon monoxide concentrations tested. This study is one of the first reports of using LJS-based powders for gas sensing applications and it highlights the suitability of the method to fabricate size- and shape-controlled nanomaterials for the detection of environmentally relevant gases.

中文翻译：

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高温合成镍基纳米颗粒，用作潜在危险气体传感器的材料

摘要

–镍铁氧体（NiFe ₂ O _4的气敏特性）和通过自持悬浮喷射合成（LJS）方法制备的氧化镍（NiO）纳米粒子。这些已与使用市售粉末制备的NiO传感器的气敏特性进行了比较。整个制造的传感器的微观结构，表面积，粒度和形态变化很大。可以预料，这些对比特性将在增强或降低材料的传感能力方面发挥关键作用。感兴趣的气体包括乙醇，甲苯和一氧化碳，并且在不同的工作温度下研究了传感器的气体响应。通常，传感器对气体的敏感度不同。在表面积较大的传感器中，当与例如基于商业的NiO传感器的灵敏度相比时，一个提供了对气体灵敏度的显着增强。镍铁₂ O ₄传感器最有希望作为乙醇的气体传感器，或多或少地对甲苯气体的气体传感器。通常，传感器对测试的一氧化碳浓度反应较差。这项研究是将基于LJS的粉末用于气体传感应用的首批报告之一，它突显了该方法适合制造尺寸和形状受控的纳米材料以检测与环境相关的气体的方法。