Kumarage Gayan W C, Panamaldeniya Shasika A, Maraloiu Valentin A, Dassanayake Buddhika S, Gunawardhana Nanda, Comini Elisabetta
SENSOR Laboratory, Department of Information Engineering, University of Brescia, Via Valotti 9, 25133 Brescia, Italy.
Department of Physics and Electronics, Faculty of Science, University of Kelaniya, Kelaniya 11600, Sri Lanka.
Sensors (Basel). 2024 Mar 14;24(6):1851. doi: 10.3390/s24061851.
Pseudohexagonal NbO microcolumns spanning a size range of 50 to 610 nm were synthesized utilizing a cost-effective hydrothermal process (maintained at 180 °C for 30 min), followed by a subsequent calcination step at 500 °C for 3 h. Raman spectroscopy analysis unveiled three distinct reflection peaks at 220.04 cm, 602.01 cm, and 735.3 cm, indicative of the pseudohexagonal crystal lattice of NbO. The HRTEM characterization confirmed the inter-lattice distance of 1.8 Å for the 110 plain and 3.17 Å for the 100 plain. The conductometry sensors were fabricated by drop-casting a dispersion of NbO microcolumns, in ethanol, on Pt electrodes. The fabricated sensors exhibited excellent selectivity in detecting CHOH (ΔG/G = 2.51 for 10 ppm CHOH) when compared to a variety of tested gases, including CO, CO, NO, H, HS, and CHO. The optimal operating temperature for this selective detection was determined to be 500 °C in a dry air environment. Moreover, the sensors demonstrated exceptional repeatability over the course of three testing cycles and displayed strong humidity resistance, even when exposed to 90% relative humidity. This excellent humidity resistance gas sensing property can be attributed to their nanoporous nature and elevated operating temperature.
利用一种经济高效的水热法（在180°C下保持30分钟）合成了尺寸范围为50至610纳米的伪六边形铌氧化物（NbO）微柱，随后在500°C下进行3小时的煅烧步骤。拉曼光谱分析揭示了在220.04厘米、602.01厘米和735.3厘米处有三个不同的反射峰，表明NbO具有伪六边形晶格。高分辨率透射电子显微镜（HRTEM）表征证实了110晶面的晶格间距为1.8埃，100晶面的晶格间距为3.17埃。通过将NbO微柱在乙醇中的分散液滴铸在铂电极上制备了电导传感器。与包括一氧化碳（CO）、二氧化碳（CO₂）、一氧化氮（NO）、氢气（H₂）、硫化氢（H₂S）和乙醇（C₂H₅OH）在内的各种测试气体相比，所制备的传感器在检测乙醇时表现出优异的选择性（对于10 ppm的乙醇，ΔG/G = 2.51）。在干燥空气环境中，这种选择性检测的最佳操作温度确定为500°C。此外，这些传感器在三个测试周期内表现出出色的重复性，并且即使暴露在90%的相对湿度下也显示出很强的耐湿性。这种优异的耐湿性气体传感特性可归因于它们的纳米多孔性质和较高的操作温度。
