Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology and Department of Electronics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300350, China.
Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology and Department of Electronics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300350, China.
J Hazard Mater. 2021 Aug 15;416:125964. doi: 10.1016/j.jhazmat.2021.125964. Epub 2021 Apr 27.
An ideal way to boost the selectivity of sensing materials is that improving the sensitivity of the target gas while suppressing that of other interfering ones. Here, the "screening behavior" of the Li doped WO nanofibers (Li/WO NFs) have been discovered in suppressing the response from interfering gases, while elevating the HS sensing response. Beneficially, the HS response of Li/WO NFs sensor prototype is three times (R / R = 64@10 ppm) as high as that of the pristine WO ones (R / R = 21@10 ppm) at ~75% relative humidity and 260 °C. Moreover, Li/WO NFs sensor prototype presents the detection limit as low as 100 ppb. Particularly, the Li/WO NFs sensors detect simulated halitosis breath, of which the accuracy is comparable with gas chromatography. Theoretically, the decrease of the responses of Li/WO NFs to interfering gases is ascribed to the enhancement of the adsorption of water molecules by Li dopant. While the improved response to HS is attributed to stronger adsorption of HS and WO and to the increased defect oxygen. The "screening behavior" of Li doped into WO NFs provides a new strategy that might improve the selectivity of other gas sensing.
提高传感材料选择性的理想方法是在提高目标气体灵敏度的同时抑制其他干扰气体的灵敏度。在这里，我们发现掺杂 Li 的 WO 纳米纤维（Li/WO NFs）具有“筛选行为”，可以抑制干扰气体的响应，同时提高 HS 的传感响应。有益的是，Li/WO NFs 传感器原型在相对湿度为 75%和 260°C 时的 HS 响应比原始 WO 纳米纤维（R / R = 21@10 ppm）高出三倍（R / R = 64@10 ppm）。此外，Li/WO NFs 传感器原型的检测限低至 100 ppb。特别是，Li/WO NFs 传感器可以检测模拟口臭呼吸，其准确性可与气相色谱法相媲美。理论上，Li 掺杂到 WO NFs 中导致对干扰气体的响应降低归因于 Li 掺杂剂增强了对水分子的吸附。而对 HS 的响应增强则归因于 HS 和 WO 的吸附增强以及缺陷氧的增加。Li 掺杂 WO NFs 的“筛选行为”为提高其他气体传感的选择性提供了一种新策略。
