Recent Progress in Chemiresistive Gas Sensing Technology Based on Molybdenum and Tungsten Chalcogenide Nanostructures

Abstract

bonding of transition metal and chalcogen atom and their crystal structure. Interestingly, all these compounds exist as layered material except tungsten oxide (WO 3 ) whose hydrated crystal (WO 3 .H 2 O) is layered in nature. [2,3] Each of these chalcogenides possesses unique features. Several micro and nanostructures of these chalcogenides have been synthesized in literature for various applications including gas sensors, biosensors, batteries, supercapacitor, photoelectrochemical and electrochromic devices. However, this review article will focus on gas sensing applications of these materials.Gas sensors play a crucial role in our life as they find applications ranging from monitoring indoor air quality to detecting highly toxic gases. Two important components of a gas sensing device are receptor and transducer. The receptor enables the chemical interaction with the target analyte molecule, which is further converted into analytical signal by the transducer. There are several transduction techniques available in gas sensing based on the physical or chemical change being measured. Broadly, they can be classified into six different classes based on sensing principles which is listed in Table 1.Chemiresistive devices have several advantages over other existing techniques. For example, the structure of these types of devices is very simple and it can be integrated with the current complementary metal oxide semiconductor (CMOS) technology. Even though, several advances have been made over last few years to improve sensing performance, the search for reliable and repeatable gas sensing element is an ongoing endeavor with lots of expectation from tungsten and molybdenum chalcogenides.After the rise of graphene, other layered materials have emerged as important functional materials for various applications of highest scientific values. Among these, layered transition metal dichalcogenides (TMDs) have a special presence as they cover whole class of materials, i.e., ranging from pure insulators to true metals. W and Mo chalcogenides are mostly semiconducting in ambient conditions and therefore, suitable for electronic application such as chemiresistive gas sensors. Though, layered TMDs (MX 2 M = Mo, and W and X = S, Se, and Te) have evolved expeditiously in a very short time, we simply cannot ignore metal oxide (particularly Mo-and W-based Chalcogens are oxygen family elements with oxygen having distinct properties than the other group members like sulfur, selenium, and tellurium. Tungsten and molybdenum chalcogenides that include mainly metal oxides (MO 3 ; M = Mo, and W) and metal dichalcogenides (MX 2 ; X = S, Se, and Te) are the most exciting class of inorganic materials. They have been widely investigated in various applications including lithium and sodium ion storage, supercapacitors, gas sensors, biosensors etc. due to their fascinating surface properties and ease of fabrication. Different class of nanostructures including 0D (nanoparticles, quantum dots), 1D (nanowires, nanotubes, nanoribbons, nanobelts etc.), a...

Rational Design of Semiconductor‐Based Chemiresistors and their Libraries for Next‐Generation Artificial Olfaction

“…CNTs, graphene or reduced graphene oxides (rGOs), transition metal dichalcogenides (TMDs), and 2D early-transition metal carbides and nitrides (MXenes) are emerging chemiresistors that can be used in artificial olfaction in the future. Because there have been many reviews on the sensing mechanisms and applications of gas sensors using CNTs, [448][449][450][451] graphene-based materials, [451][452][453][454][455][456][457][458][459][460][461] and TMDs, [452,458,[460][461][462][463] the main focus of this section will be placed on the control of gas selectivity and the design of artificial olfaction. The target gases and the operation temperatures of pristine, noble-metal-loaded, and metaloxide-loaded sensors using CNTs, graphene-based materials, and TMDs are analyzed based on recent publications in the literature (Figure 15) (sensors using graphene and rGO: publications since 2016, sensors using CNTs and TMDs: publications since 2010).…”

Advances in the designs and mechanisms of MoO3 nanostructures for gas sensors: a holistic review

“…), chalcogenides (MoSe2, WS2, WSe2, etc. ), and a few perovskite-like crystals have been acknowledged for sensing applications 33,142,143 . The 2-D materials are strong adsorbents to organic molecules, and at high temperatures, they tend to partially lose oxygen to become oxygen-deficient and so are considered as the most suitable candidates in VOCs sensing 144 .…”

Atomic‐Layer‐Deposition‐Based 2D Transition Metal Chalcogenides: Synthesis, Modulation, and Applications

“…TMCs are promising candidates for a wide range of applications such as nanoelectronics, sensors, and energy applications. [1,[11][12][13][14][15][16][17][18][19] In particular, sulfides and selenides of Group 6 elements (e.g., molybdenum and tungsten) with semiconducting properties have been widely investigated for application in nanoelectronics and sensors. [15,16,[20][21][22] The unique bandgap transition achieved by changing the number of 2D layers has drawn significant attention and ignited extensive research interest in various optoelectronic applications.…”