ZnTPyP 自組裝超分子奈米結構應用於醋酸氣體感測

Abstract

本研究利用界面活性劑溴化十六烷基三甲銨 (CTAB) 促使四吡啶基鋅卟啉 (ZnTPyP) 發生自組裝合成超分子奈米結構。接著我們比較了 ZnTPyP 微米晶體 (ZnTPyP micro crystal) 與奈米結構 (Nano material) 之氣體反應差異，並將其應用於醋酸氣體感測。ZnTPyP 之微米晶體與奈米結構皆能以穩定的形式存在溶液中，並透過 UV-Vis、SEM、TEM 及 XRD 確認結構的生成，在本實驗中將溶液滴覆於黃金指叉電極上，待其乾燥後再固定於 IC 底座上，並連接 LCR Meter 進行不同氣體之電抗測量。本研究對 15 種揮發性有機氣體進行電抗之量測，其中發現在二甲基甲醯胺 (Dimethylformamide, DMF) 及醋酸 (Acetic acid, AcOH) 具有良好的選擇性，而對其他氣體之反應較不明顯，並且在低濃度區擁有顯著的線性趨勢 (R2＞0.99)，以及良好的再現性和穩定性，透過計算後奈米結構對於醋酸的偵測下限可達 14 ppm。比較材料之反應訊號圖可以看出奈米結構的反應性優於 ZnTPyP 微米晶體，因利用界面活性劑使材料達到奈米化，使氣體易脫附於材料，因此，反應更加穩定，進而達到更低的偵測下限及穩定性。This study utilized the surfactant cetyltrimethylammonium bromide (CTAB) to induce the self-assembly of Zn(II) meso-Tetra(4-pyridyl) Porphine (ZnTPyP) into supramolecular nano structures. Subsequently, we compared the gas response differences between ZnTPyP micro crystal and nano material, and applied them to acetic acid gas sensing. Both ZnTPyP micro crystal and nano material could exist in solution in a stable form, and their structures were confirmed through UV-Vis, SEM, TEM, and XRD analyses. In this experiment, the solution was drop-casted onto gold interdigital electrodes, dried, then fixed on an IC base, and connected to an LCR Meter for gas reactance measurements.We conducted gas reactance measurements on 15 different volatile organic gases (VOCs), and found promising selectivity for dimethylformamide (DMF) and acetic acid (AcOH), with less pronounced responses to other gases. Notably, significant linear trends (R2> 0.99), reproducibility, and stability were observed in the low concentration range. Nano material exhibited a detection limit of 14 ppm for acetic acid. Comparing the reaction signal graphs of the material, it demonstrates that the nano material exhibits superior reactivity compared to ZnTPyP micro crystal. This is due to the use of surfactants to achieve nano conformation, which facilitates gas desorption from the material, resulting in a more stable reaction, a lower detection limit, and improved stability.