Co掺杂ZIF-8材料对甲醇的气敏检测

Gas Sensing Detection of Methanol Using Co-Doped ZIF-8 Materials

摘要: 为提升ZIF-8对甲醇气体的灵敏度并实现低温快速检测，本文采用水热法合成Co掺杂ZIF-8，并制备电阻型气敏器件开展性能评估。其中3% Co/ZIF-8性能最好。结果表明，在160℃、100 ppm甲醇条件下，3% Co掺杂ZIF-8的响应达到12.1，显著高于同温度下纯ZIF-8的3.2，体现出明显的敏感增强效应。同时，器件最佳工作温度相较纯ZIF-8下降20℃，说明掺杂调控有助于降低甲醇表面反应的有效能垒并拓展低温工作窗口。动态响应方面，3% Co掺杂样品的响应与恢复时间分别缩短至9 s与10 s，优于纯ZIF-8的15 s与12 s，表明其在吸附、反应与脱附过程中具有更快的动力学过程。上述结果说明Co掺杂能够在保持MOF多孔结构优势的基础上同步提升响应幅值与响应速度，为MOF基甲醇气敏材料的低温化与快速化设计提供了可复核的实验依据。

Abstract: To enhance the sensitivity of ZIF-8 towards methanol gas and achieve low-temperature rapid detection, this study synthesized Co-doped ZIF-8 via a hydrothermal method and fabricated resistive gas sensors for performance evaluation. Among the prepared samples, the 3% Co/ZIF-8 exhibited the optimal comprehensive performance. The results demonstrated that, under the conditions of 160˚C and 100 ppm methanol, the response value of 3% Co-doped ZIF-8 reached 12.1, which was significantly higher than that of pristine ZIF-8 (3.2) at the same temperature, indicating a distinct sensitivity enhancement effect. Meanwhile, the optimal operating temperature of the Co-doped sensor decreased by 20˚C compared with that of the pristine ZIF-8-based device, suggesting that doping modification helps reduce the effective energy barrier of surface reactions involving methanol and expand the low-temperature working window. In terms of dynamic response, the response and recovery times of the 3% Co-doped sample were shortened to 9 s and 10 s, respectively, outperforming those of pristine ZIF-8 (15 s and 12 s). This result indicated faster kinetic processes in the stages of adsorption, reaction and desorption for the Co-doped sample. Overall, the above findings confirm that Co doping can simultaneously improve the response magnitude and response rate while preserving the inherent advantages of the porous structure of MOFs. This work provides reproducible experimental evidence for the low-temperature and rapid-response design of MOF-based methanol gas-sensitive materials.