This work presents a room-temperature (RT) NO₂ gas sensor based on cotton-modified LaFeO₃ (CLFO) combined with MXene. LaFeO₃ (LFO), CLFO, and CLFO/MXene composites were synthesized via a hydrothermal method. The fabricated sensor, utilizing MXene/CLFO, exhibits a p-type behavior and fully recoverable sensing capabilities for low concentrations of NO₂, achieving a higher response of 14.2 times at 5 ppm. The sensor demonstrates excellent performance with a response time of 2.7 s and a recovery time of 6.2 s, along with notable stability. The sensor’s sensitivity is attributed to gas interactions on the material’s surface, adsorption energy, and charge-transfer mechanisms. Techniques such as in situ FTIR (Fourier transform infrared) spectroscopy, GC–MS (gas chromatography–mass spectroscopy), and near-ambient pressure X-ray photoelectron spectroscopy were employed to verify gas interactions and their byproducts. Additionally, finite-difference time-domain simulations were used to model the electromagnetic field distribution and provide insight into the interaction between NO₂ molecules and the sensor surface at the nanoscale. A prototype wireless IoT (Internet of Things)-based NO₂ gas leakage detection system was also developed, showcasing the sensor’s practical application. This study offers valuable insight into the development of room-temperature NO₂ sensors with a low detection limit.

中文翻译：

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使用棉改性 LaFeO3/MXene 复合材料设计超快环境 NO2 气体传感器


本工作提出了一种基于棉改性 LaFeO₃ （CLFO） 结合 MXene 的室温 （RT） NO₂ 气体传感器。采用水热法合成了 LaFeO₃ （LFO）、CLFO 和 CLFO/MXene 复合材料。采用 MXene/CLFO 制造的传感器表现出 p 型行为和对低浓度 NO₂ 的完全可恢复传感能力，在 5 ppm 时实现了 14.2 倍的响应。该传感器表现出出色的性能，响应时间为 2.7 s，恢复时间为 6.2 s，以及显着的稳定性。传感器的灵敏度归因于材料表面的气体相互作用、吸附能和电荷转移机制。采用原位 FTIR（傅里叶变换红外）光谱、GC-MS（气相色谱-质谱）和近环境压力 X 射线光电子能谱等技术来验证气体相互作用及其副产物。此外，有限差分时域仿真用于模拟电磁场分布，并在纳米尺度上深入了解 NO₂ 分子与传感器表面之间的相互作用。此外，还开发了基于无线 IoT（物联网）的 NO₂ 气体泄漏检测系统原型，展示了该传感器的实际应用。本研究为开发具有低检测限的室温 NO₂ 传感器提供了有价值的见解。