Rational Design of MoS₂/C₃N₄ Hybrid Aerogel with Abundant Exposed Edges for Highly Sensitive NO₂ Detection at Room Temperature

Abstract

The quest for advanced gas sensing materials to detect toxic gases at low temperatures has recently received much attention to ensure indoor and outdoor air quality. For this purpose, two-dimensional transition-metal dichalcogenides (TMDs) have received widespread interest due to their highly active sites for the adsorption of gas molecules and outstanding electrical, chemical, and optical properties, which enable the materials to be used as supercapacitors, electrocatalysts, photocatalysts, battery materials, and sensors. In the present work, MoS2 was vertically grown on the surface of porous C3N4 nanosheets (NSs) to form MoS2/C3N4 hybrid aerogels via freeze drying. The gas sensing performance of the composites was investigated toward NO2 gas at room temperature (RT). The as-prepared hybrid aerogel nanocomposite (MSN-2) showed abundant exposed active sites, a large number of pores, and high electronic density on the surface, thus exhibiting a 58-fold higher response than pristine MoS2 and C3N4 NSs. Furthermore, it showed short response/recovery time, commendable stability, and excellent selectivity toward NO2 gas. This work opens up an efficient way for the facile synthesis of edge-exposed MoS2 combined with highly porous C3N4 NSs for excellent NO2 gas sensing.

In Situ Synthesized Rodlike MoS2 as a Cocatalyst for Enhanced Photocatalytic Hydrogen Evolution by Graphitic Carbon Nitride without a Noble Metal

“…Obtaining an interface with close integration between the main catalyst and cocatalyst is one of the most important factors in the process of synthesis. , As for g-CN composited with MoS 2 , most works traditionally synthesized MoS 2 via a hydrothermal method and g-CN via thermal condensation, respectively, − followed by thermal treatment or sonochemical treatment to combine the two components. , Such methods are complicated in that it is not only hard to obtain a good interfacial bonding but they also increase the time and material costs during synthesis. Hence, simplifying the synthesis steps is one of the important research directions to improve the application potential of composite catalysts .…”

Two-dimensional material-based functional aerogels for treating hazards in the environment: synthesis, functional tailoring, applications, and sustainability analysis

“…5a). 106 The sensor showed long-term stability, low detection limit (10 ppb), high response speed (R a /R g = 61.07-50 ppm), and very short response/recovery time (2.1 s and 35.7 s), as shown in Fig. 5b.…”

“…Compared with pure 2DMs, 2DM aerogels not only maintain excellent optical and electrical properties, but also possess high specific surface area and more ''vacancies'' for fixing identifiers. 106 At present, 2DM aerogels have been applied as materials for the fabrication of optical and electrochemical sensors for the detection of pollutants. Optical sensors have been widely used in pollutant detection because of their high sensitivity and green environmental protection.…”

“…(c and d) SEM images of MoS 2 @C 3 N 4 aerogels. (e and f) TEM images of MoS 2 @C 3 N 4 aerogels 106. Copyright 2020, American Chemical Society.…”

Surface plasmon resonance improved photocatalytic activity of Au/TiO2 nanocomposite under visible light for degradation of pollutants

“…[28][29][30] Among the plentiful semiconductors, titanium dioxide (TiO 2 ) is the promising photocatalyst because of suitable valence band (VB) and conduction band (CB). [31][32][33][34] Although the practical applications of TO has greatly been limited due to no photo-activity under visible light, low charge separation, and difficult in recycling [35,36] , it is greatly desired to develop a feasible technique to enhance the separation of charges and to deliver strong catalytic functions for effective visible-light photocatalysis on TiO 2 (TO) for pollutant degradation. [35][36][37][38][39][40] In this work, we decorated Au nanoparticles onto the surface of TO and perceived an intensely extended light absorption and photocatalytic degradation of pollutants under visible-light irradiation.…”