Amine-functionalized metal-organic framework ZIF-8 toward colorimetric CO2 sensing in indoor air environment
Amine-functionalized metal-organic framework ZIF-8 toward colorimetric CO2 sensing in indoor air environment
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DOI：
10.1016/j.snb.2021.130313
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发表时间：
2021-06-25
影响因子：
8.4
通讯作者：
Maboudian, Roya
中科院分区：
文献类型：
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作者：
Davey, Adrian K.;Gao, Xiang;Maboudian, Roya
二氧化碳 (CO2) 已被证明会对室内人体健康造成影响，例如呼吸短促、鼻腔和视神经刺激、头晕和恶心。在这项工作中，我们探索了金属有机框架 (MOF) 作为高孔隙晶体吸附剂用于灵敏比色 CO2 检测的潜力。特别是，由于其化学稳定性和可调节的 CO2 亲和力，沸石咪唑酯骨架 (ZIF-8) 被选为吸附材料。该比色气体传感器是在甲醇中开发的，具有三种成分：(i) MOF ZIF-8 作为高表面积吸附剂； (ii) 乙二胺 (ED) 作为 CO2 亲和基函数； (iii) 酚磺酞 (PSP) 作为 pH 指示剂。比色测定和比率分析证实了对与室内空气质量相关的可变二氧化碳浓度的比色响应。颜色响应归因于两性离子机制，ED 与 CO2 反应形成两性离子中间体。然后，该中间体被 pH 指示剂去质子化，改变 pH 值并引起颜色变化。基于 ZIF-8 的比色传感器具有制造简单、响应快速、明显以及在周围环境中稳定的特点，为改善室内空气质量监测提供了一条有前途的途径。
Carbon dioxide (CO2) has been shown to contribute to human health consequences indoors, such as shortness of breath, nasal and optic irritation, dizziness, and nausea. In this work, we explore the potential of metal-organic frameworks (MOFs) as highly-porous, crystalline sorbents for sensitive colorimetric CO2 detection. In particular, the zeolitic imidazolate framework (ZIF-8) is chosen as the sorptive material due to its chemical stability and tunable CO2 affinity. The colorimetric gas sensor is developed in methanol with three components: (i) MOF ZIF-8 as a high surface area adsorbent; (ii) ethylenediamine (ED) as the CO2-affinitive basic function; and (iii) phenolsulfonpthalein (PSP) as the pH indicator. Colorimetric assays and ratiometric analysis confirm a colorimetric response to variable CO2 concentrations of relevance to indoor air quality. The color response is attributed to a zwitterion mechanism whereby ED reacts with CO2 to form a zwitterionic intermediate. This intermediate is then deprotonated by the pH indicator, shifting the pH and inducing a color change. Given its simple fabrication, rapid and obvious response, and stability in ambient environment, the ZIF-8-based colorimetric sensor provides a promising route for an improved indoor air quality monitoring.