Abstract：
The persistent challenge of poor recovery characteristics of NO2 sensors operated at room temperature remains significant. However, the development of In2O3-based gas sensing materials provides a promising approach to accelerate response and recovery for sub-ppm of NO2 detection at room temperature. Herein, we propose a simple two-step method to synthesize a one-dimensional (1D) In2O3@ZnO heterostructure material with hollow microtubes, by coupling metal-organic frameworks (MOFs) (MIL-68 (In)) and zinc ions. Meanwhile, the In2O3@ZnO composite-based gas sensor exhibits superior sensitivity performance to NO2 under visible light activation. The response value to 5 ppm of NO2 at room temperature is as high as 1800, which is 35 times higher than that of the pure In2O3-based sensor. Additionally, the gas sensor based on the In2O3@ZnO heterostructure demonstrates a significantly reduced response/recovery time of 30 s/67 s compared to the sensor based on pure In2O3 (74 s/235 s). The outstanding gas sensing properties of the In2O3@ZnO heterostructure-based sensors can be attributed to the enhanced photogenerated charge separation efficiency resulting from the heterostructure effect, and the improved receptor function toward NO2, which can increase the reactive sites and gas adsorption capacity. In summary, this work proposes a low-cost and efficient method to synthesize a 1D heterostructure material with microtube structures, which can serve as a fundamental technique for developing high-performance room-temperature gas sensors.
摘要：
在室温下操作的NO2传感器的不良恢复特性的持续挑战仍然是显著的。然而,基于In2O3的气敏材料的开发提供了一种有希望的方法来加速室温下NO2亚ppm检测的响应和恢复。在这里，我们提出了一种简单的两步法来合成具有中空微管的一维（1D）In2O3@ZnO异质结构材料，通过偶联金属-有机骨架(MOFs)(MIL-68(In))和锌离子。同时,基于In2O3@ZnO复合材料的气体传感器在可见光激活下对NO2表现出优异的灵敏度性能。室温下对5ppmNO2的响应值高达1800，是纯In2O3基传感器的35倍。此外,与基于纯In2O3的传感器（74s/235s）相比，基于In2O3@ZnO异质结构的气体传感器显着减少了30s/67s的响应/恢复时间。In2O3@ZnO异质结构传感器的出色气敏特性可归因于异质结构效应导致的光生电荷分离效率提高，并改善了对NO2的受体功能，这可以增加反应位点和气体吸附能力。总之,这项工作提出了一种低成本，高效的方法来合成具有微管结构的一维异质结构材料，它可以作为开发高性能室温气体传感器的基本技术。
