Beniwal Ajay
Department of Electronics and Communication Engineering, Indian Institute of Information Technology - Allahabad, Prayagraj, 211015, India.
Nanoscale. 2020 Oct 8;12(38):19732-19745. doi: 10.1039/d0nr05389a.
In this paper, we present a novel room temperature (RT) operated SnO2-ZnO-Fe2O3 based tri-composite analyte sensor with dual behavior having detection ability of up to ∼1 ppb with a substantial % response (R) to detect ammonia and ethanol vapors. The tri-composite is synthesized via a sol-gel spin coating technique and characterized using X-ray diffraction (XRD) for structural analysis. Fourier transform infrared spectroscopy (FTIR) and Raman results are used to confirm tri-composite formation. Further, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) results are used for examining the detailed surface morphology and structural and topographical characteristics of the tri-composite. The sensing characteristics are monitored from 1 ppb to 50 ppm for ammonia detection and 1 ppb to 25 ppm for ethanol detection at RT (∼27 °C) under ∼45% relative humidity (RH) conditions. This dual sensing behavior (based on change in resistance under ammonia and ethanol exposure) of the sensor is used to differentiate and detect the presence of ammonia (resistance decreases) and ethanol (resistance increases) with high %R within a few seconds. In addition, the sensor showed excellent sensing characteristics under moist conditions (up to 85% RH) and outstanding reproducibility, and was found to be highly stable, selective and specific towards the target analytes. This work not only reports a RT operated ppb level ammonia and ethanol sensor, but also explores the novel SnO2-ZnO-Fe2O3 tri-composite along with a scientific approach towards multi-composite nanostructures to develop analyte sensors.
在本文中，我们展示了一种新型的基于SnO₂-ZnO-Fe₂O₃的三元复合分析物传感器，该传感器在室温下运行，具有双重行为，能够检测低至约1 ppb的氨和乙醇蒸气，并具有可观的响应百分比（R）。该三元复合材料通过溶胶-凝胶旋涂技术合成，并使用X射线衍射（XRD）进行结构分析。傅里叶变换红外光谱（FTIR）和拉曼光谱结果用于确认三元复合材料的形成。此外，场发射扫描电子显微镜（FESEM）、高分辨率透射电子显微镜（HRTEM）和原子力显微镜（AFM）结果用于研究三元复合材料的详细表面形态、结构和形貌特征。在室温（约27°C）和约45%相对湿度（RH）条件下，监测氨检测从1 ppb到50 ppm以及乙醇检测从1 ppb到25 ppm的传感特性。传感器的这种双重传感行为（基于氨和乙醇暴露下电阻的变化）用于在几秒钟内以高响应百分比（%R）区分和检测氨（电阻降低）和乙醇（电阻增加）的存在。此外，该传感器在潮湿条件下（高达85% RH）表现出优异的传感特性和出色的重现性，并且对目标分析物具有高度稳定性、选择性和特异性。这项工作不仅报道了一种室温运行的ppb级氨和乙醇传感器，还探索了新型的SnO₂-ZnO-Fe₂O₃三元复合材料以及一种针对多复合纳米结构开发分析物传感器的科学方法。
