Zhang Xu, Tian Bo, Ma Zhiheng, Wang He, Cheng Zhixuan, Xu Jiaqiang
NEST Laboratory, Department of Chemistry, College of Science, Shanghai University, Shanghai 200444, China.
Nanomaterials (Basel). 2023 Jul 14;13(14):2072. doi: 10.3390/nano13142072.
As a volatile air pollutant, formaldehyde can enter people's living environment through interior decoration, furniture and paint, causing serious harm to human health. Therefore, it is necessary to develop a sensor for the real-time detection of formaldehyde in low concentrations. According to the chemical interaction between amino groups and formaldehyde, a MIL-101(Cr) aminated-material-based formaldehyde cantilever sensor was prepared, of which ethylenediamine- functionalized MIL-101(Cr) named ED-MIL-101(Cr)) showed the best gas sensing performance. Using quasi-in situ infrared spectroscopy, ED-MIL-101(Cr) was found bound to formaldehyde through a Schiff base. The adsorption enthalpy of formaldehyde-bound ED-MIL-101(Cr) was -52.6 kJ/mol, which corresponds to weak chemical adsorption, so the material showed good selectivity. In addition, ED-MIL-101(Cr) has the most active sites, so its response value to formaldehyde is larger and it takes longer to reach saturation adsorption than bare MIL-101(Cr). Through the research on the gas sensing performance of functionalized MIL-101(Cr) material, we found that it has a strong application potential in the field of formaldehyde monitoring, and the material performance can be quantitatively and accurately evaluated through combining calculation and experimentation for understanding the gas sensing mechanism.
作为一种挥发性空气污染物，甲醛可通过室内装修、家具及油漆进入人们的生活环境，对人体健康造成严重危害。因此，有必要开发一种用于实时检测低浓度甲醛的传感器。根据氨基与甲醛之间的化学相互作用，制备了一种基于MIL-101(Cr)胺化材料的甲醛悬臂梁传感器，其中乙二胺功能化的MIL-101(Cr)（命名为ED-MIL-101(Cr)）表现出最佳的气敏性能。通过准原位红外光谱发现，ED-MIL-101(Cr)通过席夫碱与甲醛结合。甲醛结合的ED-MIL-101(Cr)的吸附焓为-52.6 kJ/mol，这对应于弱化学吸附，因此该材料表现出良好的选择性。此外，ED-MIL-101(Cr)具有最多的活性位点，所以其对甲醛的响应值更大，且达到饱和吸附所需的时间比裸MIL-101(Cr)更长。通过对功能化MIL-101(Cr)材料气敏性能的研究，我们发现它在甲醛监测领域具有很强的应用潜力，并且通过结合计算和实验可以定量准确地评估材料性能，以了解气敏机制。
