Facile Synthesis of Conductive Metal−Organic Frameworks Nanotubes for Ultrahigh‐Performance Flexible NO Sensors

Abstract

Additionally, the number of Cu 2c (the Cu 2c in the crystal defects bound with two S atoms) in the Cu-BHT structure is the primary factor affecting the Cu-BHT-based sensing devices' performance. [6,17] However, the Cu-BHT's crystal structure makes its specific surface smaller than that of the conventional metal-organic frameworks, which significantly affects its application in electrocatalysts and sensors. Thus, the preparation of Cu-BHT with a large surface area and abundant Cu 2c on the surface is a crucial factor in improving the performance of Cu-BHT-based devices.Gaseous pollutants, emitted by car engines or other combustion processes, are attracting attention because of their threat to the human body, such as physiological dysfunctions, chronic bronchitis, and lung cancer. [18][19][20][21][22][23][24][25][26][27][28] Consequently, various materials have been utilized to detect toxic gases, such as metal oxide semiconductors, [29,30] MXene/noble metal, [31][32][33][34] ion-conducting hydrogels, and organohydrogels. [35,36] Among gaseous pollutants, nitric oxide (NO), as a marker for airway inflammations, plays a major role in biological functions and pathological processes. [37,38] Measurement of exhaled NO has applications in diagnosing and monitoring inflammation, and the information obtained can be used as a tool for managing asthma treatment. Therefore, developing sensors to detect NO gas is critical for diagnosing and monitoring an asthma patient or ambient monitoring.Among different types of NO gas sensors, organic field-effect transistor (OFET) based sensors are increasingly attracting attention owing to their gate-induced tunable channel conductivities, amplification effects, concurrent actualization of processing, memory functions, miniaturized size, solution processing, and low power consumption. [39,40] Alternatively, many parameters, such as transport mobility (μ), threshold voltage (V Th ), current on/off ratio (I on /I off ), and subthreshold swing (SS), can be characterized the gas-sensing performance in a sensor based on an OFET device. In addition, the electronic properties of the semiconductor materials can be flexibly tuned to improve specificity. [41] However, due to the weak affinity with NO gas, the OFET device's sensitivity to detect NO gas was limited. Recently, the formation of heterostructure is known to be a promising strategy to enhance sensitivity and improve selectivity of gas sensing. [42][43][44] Cu-benzenehexathiol (Cu-BHT) has attracted significant attention due to its record high electrical conductivity and crystal defects Cu 2c . However, the nonporous structure and small specific surface area of Cu-BHT with twodimensional kagome lattice invariably limit its practical application in sensing and catalysis. In this work, Cu-BHT nanotubes (Cu-BHT-NTs) are designed and prepared via a facile homogeneous reaction to solve these problems. Compared with the traditional nanorod-like structure, the Cu-BHT-NTs not only have a higher specific surface area but also possess a higher pro...

Chemical Vapor Deposition and High-Resolution Patterning of a Highly Conductive Two-Dimensional Coordination Polymer Film

“…The binding energies (BE) of 953.1 and 932.3 eV correspond to the Cu 2p 1/2 and 2p 3/2 regions, respectively. As shown in Figure f, the Cu 2p 3/2 region shows a main peak at 932.6 eV with a shoulder at higher BE and no significant satellite peaks, thus pointing to the exclusive presence of Cu I , in line with previously reported X-ray photoelectron spectroscopy (XPS) measurements of Cu-BHT. ,,,, Since the sputtered starting material is predominantly composed of CuO with a minor fraction of Cu 0 (Figure S12), the reduction of Cu II to Cu I must occur during the vapor–solid reaction with H 6 BHT. Based on previous studies of Cu-thiolate self-assembled mono- and multilayers, , we hypothesize that first CuO can be reduced via the oxidation of the thiol groups in H 6 BHT to disulfides, followed by the formation of Cu–thiolate bonds with the excess vaporized linkers.…”

“…As shown in Figure 2f, the Cu 2p 3/2 region shows a main peak at 932.6 eV with a shoulder at higher BE and no significant satellite peaks, thus pointing to the exclusive presence of Cu I , in line with previously reported X-ray photoelectron spectroscopy (XPS) measurements of Cu-BHT. 15,37,44,45,47 Since the sputtered starting material is predominantly composed of CuO with a minor fraction of Cu 0 (Figure S12), the reduction of Cu II to Cu I must occur during the vapor−solid reaction with H 6 BHT.…”

Solution-processed filamentous copper phthalocyanine films for enhanced NO2 gas sensing at room temperature

“…The response rate of NO 2 gas detection was significantly improved (from 122% to 1053% at 30 ppm), along with ultra-low LOD (∼2.3 ppb) and good gas selectivity. Wang 18 prepared DPPTT/Cu-BHT nanotubes heterostructure OFET-based sensors. The sensors had excellent selectivity for NO toxic gas, up to 13 610%, the LOD of 5 ppb.…”

Theoretical Insights into the Selective Electrocatalytic Reduction of NO to NH3 on a Two-Dimensional Cu-Benzylthiol Metal–Organic Framework Nanostructure

“…Moreover, Wang et al developed a sensing device based on Cu-BHT nanotubes, which showed excellent selectivity and sensitivity in the detection of NO. 35 Hence, we take the metal−organic framework Cu-BHT monolayer nanostructure as a representative model to conduct a first-principles investigation to comprehensively understand the reduction reaction mechanism of NO to NH 3 catalyzed by TM-BHT. In contrast to copper metal, the Cu-BHT monolayer nanostructure boasts a significantly larger specific surface area, resulting in a substantially higher density of active sites.…”