Layered amorphous a-SnO2 gas sensors by controlled oxidation of 2D-SnSe2

Paolucci, Valentina; Santis, Jessica De; Lozzi, L.; Giorgi, Giacomo; Cantalini, C.

doi:10.1016/j.snb.2021.130890

Cited by 14 publications

(23 citation statements)

References 66 publications

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“…E ads is in eV, and the Bader charge is in elementary charge units. E ads are values obtained by combining AIMD+DFT approaches for E surf_H2S and (in brackets) values obtained still by combining AIMD+DFT approaches for the calculation of both E surf_H2S and E surf terms in eq S1 in Supporting Information, Section S4 , which is the same for C2 , i.e., the most stable anchoring mechanism of H 2 O as described in ref ( 28 ). A Bader charge of >0 indicates charge transfer from the adsorbed species to the a -SnO 2 surface.…”

Section: Resultsmentioning

confidence: 99%

“…In the same fashion, as shown in the right-hand side of Figure 8 b following a heterolytic rupture of OH bonds in H 2 O, 28 water vapor chemisorbs over the a -SnO 2 surface with the formation of a rooted hydroxyl, two-fold coordinated with surface Sn atoms indicated as (OH) 2Sn , and one rooted hydroxyl group (OH) O . Corresponding energetics and Bader charges are shown in the last line of Table 3 , referring to the most stable H 2 O attack (specifically C2 in ref ( 28 )).…”

Section: Resultsmentioning

confidence: 99%

“…In this case, the Bader analysis reveals an enhanced electron localization on S (−0.71), a fingerprint of the more marked electronegativity of S (compared to that of Sn, i.e., 2.58 vs 1.96). 75 The last structure (3 in Figure 7 In the same fashion, as shown in the right-hand side of Figure 8b following a heterolytic rupture of OH bonds in H 2 O, 28 water vapor chemisorbs over the a-SnO 2 surface with the formation of a rooted hydroxyl, two-fold coordinated with surface Sn atoms indicated as (OH) 2Sn , and one rooted hydroxyl group (OH) O . Corresponding energetics and Bader charges are shown in the last line of Table 3, referring to the most stable H 2 O attack (specifically C2 in ref 28).…”

Section: Theoretical Model Of H 2 S and Humidity Adsorptionmentioning

confidence: 91%

mentioning

confidence: 99%

“…The difficulty of controlling the final thickness of the growing a-SnO 2 oxide over the 2D crystalline platform and the risk that the a-SnO 2 film is not self-passivating, i.e., not protecting the underlying 2D layer from further oxidation, make their practical exploitation challenging. 28 Departing from liquid-phase exfoliated SnSe 2 layers (10−30 nm thick) and controlling the oxidation in air at 250 °C for two weeks, at temperatures below the crystallization temperature of a-SnO 2 oxide (i.e., ≈280 °C), we show for the first time that the oxidation process of 2D SnSe 2 can be successfully driven to the "core" of the flakes, yielding single-phase, fully amorphous 2D a-SnO 2 , which is stable up to 250 °C and sensitive to H 2 S gas (400 ppb to 1.5 ppm) and to humid air (10−80% RH (relative humidity) (RH @ 25 °C)) at a 100 °C operating temperature. Layered amorphous metal oxide sensors (LAMOS) like a-SnO 2 can be easily manufactured in a thin-film form by standard spin-coating deposition techniques representing a new interface for chemoresistive gas sensing applications.…”

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confidence: 99%

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Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity

et al. 2022

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Two-dimensional (2D) transition metal dichalcogenides (TMDs) and metal chalcogenides (MCs), despite their excellent gas sensing properties, are subjected to spontaneous oxidation in ambient air, negatively affecting the sensor’s signal reproducibility in the long run. Taking advantage of spontaneous oxidation, we synthesized fully amorphous a -SnO 2 2D flakes (≈30 nm thick) by annealing in air 2D SnSe 2 for two weeks at temperatures below the crystallization temperature of SnO 2 ( T < 280 °C). These engineered a -SnO 2 interfaces, preserving all the precursor’s 2D surface-to-volume features, are stable in dry/wet air up to 250 °C, with excellent baseline and sensor’s signal reproducibility to H 2 S (400 ppb to 1.5 ppm) and humidity (10–80% relative humidity (RH)) at 100 °C for one year. Specifically, by combined density functional theory and ab initio molecular dynamics, we demonstrated that H 2 S and H 2 O compete by dissociative chemisorption over the same a -SnO 2 adsorption sites, disclosing the humidity cross-response to H 2 S sensing. Tests confirmed that humidity decreases the baseline resistance, hampers the H 2 S sensor’s signal (i.e., relative response (RR) = R a / R g ), and increases the limit of detection (LOD). At 1 ppm, the H 2 S sensor’s signal decreases from an RR of 2.4 ± 0.1 at 0% RH to 1.9 ± 0.1 at 80% RH, while the LOD increases from 210 to 380 ppb. Utilizing a suitable thermal treatment, here, we report an amorphization procedure that can be easily extended to a large variety of TMDs and MCs, opening extraordinary applications for 2D layered amorphous metal oxide gas sensors.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Theoretical Model Of H 2 S and Humidity Adsorptionmentioning

confidence: 91%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity

et al. 2022

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Surface trapping induced negative photoconductivity in Au nanoparticles functionalized SnO2/SnSe2 nanosheets under visible and NIR light

Rathore,

Hazra

2024

FlatChem

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Amorphous Bimetallic Cobalt-Based Transition-Metal Oxides for Gas Sensing Application with Regulated Selectivity

Li,

Hu,

Fang

et al. 2024

ACS Appl. Electron. Mater.

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Amorphous materials have great potential application in gas sensors due to their abundant active sites. However, it is still a challenge to regulate their sensing performance. In this work, we developed a synthesis method of amorphous bimetallic cobalt-based transition-metal oxides, which were prepared via two steps, namely, coprecipitation of bimetallic hydroxides and then annealing at elevating temperature. Sn, Mg, and Zn as the second metal were introduced to prepare amorphous CoSn–O, CoMg–O, and CoZn–O. They were further used to fabricate gas sensors. A sensing investigation revealed that the sensors present different sensing behaviors, in which the CoSn–O, CoMg–O, and CoZn–O sensors show selectivity to TEA, EtOH, and n-BuNH2, respectively. A sensor array based on these three types of sensors was constructed. The actual concentrations of the mixing gases of TEA, EtOH, and n-BuNH2 can be obtained by matrix calculation with an error value of less than 10%. Finally, the sensing processes were discussed, and the sensing mechanism can be attributed to the surface resistance control model. This research affords a convenient method to synthesize amorphous bimetallic oxides with regulated properties for sensing application.

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Layered amorphous a-SnO2 gas sensors by controlled oxidation of 2D-SnSe2

Cited by 14 publications

References 66 publications

Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity

Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity

Surface trapping induced negative photoconductivity in Au nanoparticles functionalized SnO2/SnSe2 nanosheets under visible and NIR light

Amorphous Bimetallic Cobalt-Based Transition-Metal Oxides for Gas Sensing Application with Regulated Selectivity

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Layered amorphous a-SnO2 gas sensors by controlled oxidation of 2D-SnSe2

Cited by 14 publications

References 66 publications

Bidimensional Engineered Amorphous a-SnO2 Interfaces: Synthesis and Gas Sensing Response to H2S and Humidity

Bidimensional Engineered Amorphous a-SnO2 Interfaces: Synthesis and Gas Sensing Response to H2S and Humidity

Surface trapping induced negative photoconductivity in Au nanoparticles functionalized SnO2/SnSe2 nanosheets under visible and NIR light

Amorphous Bimetallic Cobalt-Based Transition-Metal Oxides for Gas Sensing Application with Regulated Selectivity

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Product

Resources

About

Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity

Bidimensional Engineered Amorphous a-SnO₂ Interfaces: Synthesis and Gas Sensing Response to H₂S and Humidity