Thin 2D: The New Dimensionality in Gas Sensing

Abstract

Abstract:Since the first report of graphene, thin two-dimensional (2D) nanomaterials with atomic or molecular thicknesses have attracted great research interest for gas sensing applications. This was due to the distinctive physical, chemical, and electronic properties related to their ultrathin thickness, which positively affect the gas sensing performances. This feature article discusses the latest developments in this field, focusing on the properties, preparation, and sensing applications of thin 2D inorganic nanomaterials such as single-or few-layer layered double hydroxides/transition metal oxides/transition metal dichalcogenides. Recent studies have shown that thin 2D inorganic nanomaterials could provide monitoring of harmful/toxic gases with high sensitivity and a low concentration detection limit by means of conductometric sensors operating at relatively low working temperatures. Promisingly, by using these thin 2D inorganic nanomaterials, it may open a simple way of improving the sensing capabilities of conductometric gas sensors.

Gold Decoration and Photoresistive Response to Nitrogen Dioxide of WS2 Nanotubes

“…It is clearly seen that the slope coefficients do not exceed 0.20, which is far below the typical slope of 1 predicted for the R gas / R air ratios originating from competitive chemisorption of oxygen and oxidizing gas on the semiconductor grains . Obviously, this corroborates the physisorption‐charge transfer mechanism of NO 2 interaction with NT‐WS 2 ‐based materials, rather than chemisorption, which is in agreement with the previous reports on gas‐TMDC interactions . It should be noted that Au‐NT‐WS 2 nanocomposites demonstrate better photoresponse as compared to pristine NT‐WS 2 (Figure b).…”

Supercritical Fluid‐Facilitated Exfoliation and Processing of 2D Materials

“…2D materials have been extensively developed as wet chemical and gas phase sensors, and reviews of their applications focusing on GO, [242,243] rGO, [243] and graphene, [243,245] chalcogenides, [244][245][246][247][248][249] oxides, [248] and layer-by-layer [242,250] assemblies are available. In all electrochemical-based sensing, it is important to maintain good electrical conductivity in a sensor-intended composite material, similarly to 2D materials used in electrocatalysis.…”

Novel 2D-Inorganic Materials for Gas Sensing

“…In introducing the feature review, Prof. Neri presented and discussed the general properties of thin 2D-inorganic nanomaterials [5]. Features of single-or few-layered double hydroxides/transition metal oxides/transition metal dichalcogenides have been reviewed.…”