Although the relative response of metal oxide chemiresistive gas sensors has been greatly improved by using their nanostructures as sensing units, it remains challenging to recognize the detected gases due to their intrinsic cross-sensing properties. Here, by considering the temperature dependence of the sensing activity for metal oxide gas sensors, the dynamic sensing behavior of CdO (9 at%)-decorated porous ZnO nanobelts as an example was systematically investigated under a continuously changing working temperature. This working temperature modulation was achieved by precisely manipulating high and low heating voltages with a rectangular wave mode. In some working temperature ranges, the fabricated gas sensor exhibited characteristic response curves toward propanol, isopropanol, and ethanol, which were discriminated from other investigated volatile organic compounds (VOCs). Under periodical working temperature modulation, their characteristic response curves were repeatable and stable. In addition, the relationships between the relative responses at characteristic sensing temperature points and their concentrations were investigated. This work offers a promising strategy for using sensing nanomaterials for the highly sensitive recognition and analysis of VOCs, while avoiding cross-sensing.

中文翻译：

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基于 CdO 修饰的多孔 ZnO 纳米带的温度调制气体传感器，用于可识别检测乙醇、丙醇和异丙醇


尽管金属氧化物化学电阻气体传感器的相对响应通过使用其纳米结构作为传感单元而得到了极大的改善，但由于其固有的交叉传感特性，识别检测到的气体仍然具有挑战性。在此，通过考虑金属氧化物气体传感器传感活性的温度依赖性，以CdO（9 at%）修饰的多孔ZnO纳米带为例，系统地研究了在连续变化的工作温度下的动态传感行为。这种工作温度调制是通过使用矩形波模式精确控制高低加热电压来实现的。在某些工作温度范围内，所制造的气体传感器表现出对丙醇、异丙醇和乙醇的特征响应曲线，这与其他研究的挥发性有机化合物（VOC）不同。在周期性工作温度调制下，其特性响应曲线重复性好且稳定。此外，还研究了特征传感温度点的相对响应与其浓度之间的关系。这项工作为使用传感纳米材料对 VOC 进行高灵敏度识别和分析提供了一种有前途的策略，同时避免了交叉传感。