Reduced graphene oxide hybridized with WS2 nanoflakes based heterojunctions for selective ammonia sensors at room temperature

Wang, Xueyan; Gu, Dawei; Li, Xiaogan; Lin, Shisheng; Zhao, Shuheng; Rumyantseva, M. N.; Gaskov, Alexander

doi:10.1016/j.snb.2018.11.080

Cited by 124 publications

(64 citation statements)

References 52 publications

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“…This is probably due to the high polarity and capability of NH3 to donate electrons to the surface molecules of the sensor. These results are in agreement with findings by different researchers about the selectivity of various WS2 sensors to interferents [2,17,31,35]. The specificity values for each analyte are summarized in Table S4.…”

Section: Specificity Of the Ola/ws2 (45 Min) To Selected Vocs At 25% Rhsupporting

confidence: 91%

“…This is a result of depletion of [2,17,30]. WS2 has a strong Lewis acid surface that is strongly attracted to NH3, a Lewis base [31]. Of the three sensors (15, 45 and 60 min), the 45 min derived OLA/WS2 displayed the highest negative sensitivity followed by 15 and 60 min (sensitivities for all reaction times are summarized in Table S3).…”

Section: Sensitivity Of the Ola/ws2 Based Sensorsmentioning

confidence: 99%

See 1 more Smart Citation

Limiting the Oxidation of WS2 Nanostructures by Oleylamine Surface Passivation for Room Temperature NH3 Sensing

Gqoba¹,

Rodrigues²,

Mphahlele³

et al. 2020

Preprint

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Oleylamine capped WS2 nanostructures were successfully formed at 320 °C via a relatively simple colloidal route. SEM and TEM analyses showed that the 3D nanoflowers that were initially formed disintegrated into 2D nanosheets after prolonged incubation. XPS and XRD analyses confirmed oxidation of WS2 into WO3. Sensors based on these oleylamine capped WS2 nanoflowers and nanosheets still showed a change in electrical response towards various concentrations of NH3 vapour at room temperature in a 25% relative humidity background despite the oxidation. The nanoflowers exhibited n-type response while the nanosheets displayed a p-type response towards NH3 exposure. The nanoflower based sensors showed better response to NH3 vapour exposure than the nanosheets. The sensors showed a good selectivity towards NH3 relative to acetone, ethanol, chloroform and toluene. Meanwhile, a strong interference of humidity to the NH3 response was displayed at high relative humidity levels. The results demonstrated that oleylamine limited the extent of oxidation of WS2 nanostructures. The superior sensing performance of the nanoflowers can be attributed to their hierarchical morphology which enhances the surface area and diffusion of the analyte.

show abstract

Section: Specificity Of the Ola/ws2 (45 Min) To Selected Vocs At 25% Rhsupporting

confidence: 91%

Section: Sensitivity Of the Ola/ws2 Based Sensorsmentioning

confidence: 99%

Limiting the Oxidation of WS2 Nanostructures by Oleylamine Surface Passivation for Room Temperature NH3 Sensing

Gqoba¹,

Rodrigues²,

Mphahlele³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…The thermal treatment is the simplest way to reduce GO [26][27][28]. Many of the thermal reduction steps to form rGO are performed hydrothermally in an autoclave to reduce the precursor material under high temperature and pressure [22,29,30].…”

Section: Chemical Exfoliationmentioning

confidence: 99%

Recent developments in carbon-based two-dimensional materials: synthesis and modification aspects for electrochemical sensors

Kirchner

Hirsch

2020

Microchim Acta

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This review (162 references) focuses on two-dimensional carbon materials, which include graphene as well as its allotropes varying in size, number of layers, and defects, for their application in electrochemical sensors. Many preparation methods are known to yield two-dimensional carbon materials which are often simply addressed as graphene, but which show huge variations in their physical and chemical properties and therefore on their sensing performance. The first section briefly reviews the most promising as well as the latest achievements in graphene synthesis based on growth and delamination techniques, such as chemical vapor deposition, liquid phase exfoliation via sonication or mechanical forces, as well as oxidative procedures ranging from chemical to electrochemical exfoliation. Two-dimensional carbon materials are highly attractive to be integrated in a wide field of sensing applications. Here, graphene is examined as recognition layer in electrochemical sensors like field-effect transistors, chemiresistors, impedance-based devices as well as voltammetric and amperometric sensors. The sensor performance is evaluated from the material’s perspective of view and revealed the impact of structure and defects of the 2D carbon materials in different transducing technologies. It is concluded that the performance of 2D carbon-based sensors is strongly related to the preparation method in combination with the electrical transduction technique. Future perspectives address challenges to transfer 2D carbon-based sensors from the lab to the market.

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“…A giant improvement (862.8 times improvement) in sensors' response was observed over pure WS 2 nanosheet based humidity sensor owing to the synergistic effect at the interfaces. Wang et al prepared WS 2 /RGO heterojunction by one step hydrothermal technique and demonstrated its excellent near room temperature (33.5 °C) ammonia gas sensing performance for the concentration range of 10–50 ppm 216. The introduction of more hydroxyl ions as well as extra Lewis acid active centers in RGO matrix IS two important reasons behind the performance enhancement of this heterogeneous material‐based devices.…”

Section: Efforts To Improve Performance Of Devices Based On These Matmentioning

confidence: 99%

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

Jha

Bhat

2020

Adv Materials Inter

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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...

show abstract

Reduced graphene oxide hybridized with WS2 nanoflakes based heterojunctions for selective ammonia sensors at room temperature

Cited by 124 publications

References 52 publications

Limiting the Oxidation of WS2 Nanostructures by Oleylamine Surface Passivation for Room Temperature NH3 Sensing

Limiting the Oxidation of WS2 Nanostructures by Oleylamine Surface Passivation for Room Temperature NH3 Sensing

Recent developments in carbon-based two-dimensional materials: synthesis and modification aspects for electrochemical sensors

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

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