Water-Selective Nanostructured Dehumidifiers for Molecular Sensing Spaces

Abstract

Humidity and moisture effects, frequently called water poisoning, in surroundings are inevitable for various molecular sensing devices, strongly affecting their sensing characteristics. Here, we demonstrate a water-selective nanostructured dehumidifier composed of ZnO/TiO 2 /CaCl 2 core− shell heterostructured nanowires for molecular sensing spaces. The fabricated nanostructured dehumidifier is highly water-selective without detrimental adsorptions of various volatile organic compound molecules and can be repeatedly operated. The thermally controllable and reversible dehydration process of CaCl 2 •nH 2 O thin nanolayers on hydrophilic ZnO/TiO 2 nanowire surfaces plays a vital role in such water-selective and repeatable dehumidifying operations. Furthermore, the limitation of detection for sensing acetone and nonanal molecules in the presence of moisture (relative humidity ∼ 90%) was improved more than 20 times using nanocomposite sensors by operating the developed nanostructured dehumidifier. Thus, the proposed water-selective nanostructured dehumidifier offers a rational strategy and platform to overcome water poisoning issues for various molecular and gas sensors.

Detection of DMF and NH3 at Room Temperature Using a Sensor Based on a MoS2/Single-Walled Carbon Nanotube Composite

“…Thus, the sensor retains a relatively high sensing performance in a humid environment, but a small humidity correction would likely be required for practical application. The decrease in the response is attributed to the adsorption of a small amount of water on the sensing material; the results are similar to those in previous reports. , …”

“…The decrease in the response is attributed to the adsorption of a small amount of water on the sensing material; the results are similar to those in previous reports. 10,53 Stability, or repeatability, and long-term durability are important for evaluating the performance of practical gas sensors. Figure 6(d For instance, in MoS 2 , with layered structure, the gas molecules may get trapped and once the surface is covered, for increasing concentration, excess molecules may not get the sufficient sites to attach themselves.…”

Mechanism of Interfacial Molecular Interactions Reveals the Intrinsic Factors for the Highly Enhanced Sensing Performance of Ag-Loaded Co3O4

“…5,6 The gas− solid interfacial interactions could be effectively modulated by altering the compositions or structures of the sensing material, which could further improve the response performances of metal oxide gas sensors. 7,8 The general strategies include heteroatom doping, heterojunction engineering, metal loading, morphology controlling, and so on. 9−13 Among these approaches, the noble metal (Au, Ag, Pd, etc.…”

“…The gas–solid interfacial interactions between gaseous molecules and sensing materials play a critical role in the sensing performance of metal oxide gas sensors. − These interactions, such as interfacial sensing reactions of gas molecules, adsorption–desorption processes of surface species, and structural dynamics of sensing materials, could significantly contribute to changes in sensors’ electrical signals. , The gas–solid interfacial interactions could be effectively modulated by altering the compositions or structures of the sensing material, which could further improve the response performances of metal oxide gas sensors. , The general strategies include heteroatom doping, heterojunction engineering, metal loading, morphology controlling, and so on. − Among these approaches, the noble metal (Au, Ag, Pd, etc. )-loading strategy could increase gas response, decrease working temperature, and improve selectivity of metal oxide sensors. − The improved gas-sensing performances of metal oxide gas sensors loaded with precious metals are usually attributed to electronic and chemical sensitization effects.…”

Progress and Perspectives of Single‐Atom Catalysts for Gas Sensing

“…Gas sensors are widely applied in various areas including health care, [ 1 ] environmental protection, [ 2 ] smart home, [ 3 ] and wearable devices. [ 4 ] Toxic gases emitted by industrial production and transportation not only cause serious environmental pollution but also seriously threaten human health.…”