Garg Deepika, Rekhi Heena, Kaur Harpreet, Singh Karamjit, Malik Ashok Kumar
Department of Chemistry, Punjabi University, Patiala-147 002, Punjab, India.
GSSDGS Khalsa College, Patiala-147 001, Punjab, India.
J Fluoresc. 2022 May;32(3):1171-1188. doi: 10.1007/s10895-022-02902-9. Epub 2022 Mar 26.
Multifunctional Cu (II)-based Metal Organic Framework (MOF) [Cu(BTC)] has been synthesized by a facile electrochemical method. Crystallographic and morphological characterizations of synthesized MOF have been done using Powder X-ray Diffractometer and Scanning Electron Microscope (SEM), respectively, whereas Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive X-ray Spectroscopy (EDS), UV-Vis Absorption Spectroscopy and Energy Resolved Luminescence Spectroscopic studies have been used for the detailed qualitative, quantitative as well as optical analyses. Sharp PXRD peaks indicate the formation of highly crystalline MOF with face centered cubic (fcc) structure. Flakes (average length = 0.71 µm and width = 0.10 µm) and rods (average aspect ratio = ((0.1:8.3) µm) like morphologies have been observed in SEM micrographs. The presence of C, O and Cu has been confirmed by EDS analysis. Photocatalytic activity potential of the synthesized MOF has been tested using methylene blue dye (MB) as a test contaminant in aqueous media under sunlight irradiation. Selective and sensitive fluorescent sensing of different Nitroaromatic compounds (NACs) like 4-Nitroaniline (4-NA), 2-Nitroaniline (2-NA), 3-Nitroaniline (3-NA), 4-Nitrotoulene (4-NT), 2,4-Dinitrotoulene (2,4-DNT), 1,3-Dinitrobenzene (1,3-DNB), 2,6- Dinitrotoulene (2,6-DNT) has been done by exploring the photoluminescent behaviour of chemically stable Cu(BTC). Synthesized MOF is extremely sensitive towards 4-NA, which is having PL quenching efficiency of 82.61% with highest quenching rate till reported. Indeed, a large quenching coefficient KSV = 34.02 × 10 M and correlation coefficient R = 0.9962 in K plot have been elucidated with limit of detection (LOD) = 0.7544 ppb. The possible ways of luminescence quenching are successfully explained by the combination of Photoinduced Electron Transfer (PET) and Resonance Energy Transfer (RET) mechanisms. Additionally, the Density Functional Theory (DFT) calculations have been employed to support the experimental results. Cu(BTC) fully demonstrates the power of a multi component MOF, which provides a feasible pathway for the design of novel material towards fast responding luminescence sensing and photocatalytic degradation of pollutants.
通过一种简便的电化学方法合成了多功能铜（II）基金属有机框架（MOF）[Cu（BTC）]。分别使用粉末X射线衍射仪和扫描电子显微镜（SEM）对合成的MOF进行了晶体学和形态学表征，而傅里叶变换红外光谱（FT-IR）、能量色散X射线光谱（EDS）、紫外可见吸收光谱和能量分辨发光光谱研究则用于详细的定性、定量以及光学分析。尖锐的PXRD峰表明形成了具有面心立方（fcc）结构的高度结晶的MOF。在SEM显微照片中观察到了片状（平均长度=0.71 µm，宽度=0.10 µm）和棒状（平均纵横比=（（0.1:8.3）µm））的形态。EDS分析证实了C、O和Cu的存在。在阳光照射下，以亚甲基蓝染料（MB）作为测试污染物，测试了合成的MOF在水介质中的光催化活性潜力。通过探索化学稳定的Cu（BTC）的光致发光行为，对不同的硝基芳香族化合物（NACs），如4-硝基苯胺（4-NA）、2-硝基苯胺（2-NA）、3-硝基苯胺（3-NA）、4-硝基甲苯（4-NT）、2,4-二硝基甲苯（2,4-DNT）、1,3-二硝基苯（1,3-DNB）、2,6-二硝基甲苯（2,6-DNT）进行了选择性和灵敏的荧光传感。合成的MOF对4-NA极其敏感，其PL猝灭效率为82.61%，是迄今报道的最高猝灭率。实际上，在K图中阐明了大的猝灭系数KSV = 34.02×10 M和相关系数R = 0.9962，检测限（LOD）= 0.7544 ppb。通过光致电子转移（PET）和共振能量转移（RET）机制的结合成功解释了发光猝灭的可能方式。此外，采用密度泛函理论（DFT）计算来支持实验结果。Cu（BTC）充分展示了多组分MOF的能力，为设计用于快速响应发光传感和光催化降解污染物的新型材料提供了一条可行的途径。
