Sn-doping induced oxygen vacancies on the surface of the In2O3 nanofibers and their promoting effect on sensitive NO2 detection at low temperature

Ri, Jisong; Li, Xiaowei; Shao, Changlu; Liu, Yu; Han, Chaohan; Liu, Yichun

doi:10.1016/j.snb.2020.128194

Cited by 62 publications

(17 citation statements)

References 46 publications

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“…A variety of metal oxides, such as In 2 O 3 , ZnO, SnO 2 , WO 3 , and NiO, are investigated as gas-sensing materials . Among these rich family of metal oxides, In 2 O 3 , possessing the distinctive merits of a wider band gap (3.55–3.75 eV), lower electrical resistivity, and higher electric conductivities, has proven to be an ideal gas-sensor material. , In particular, In 2 O 3 morphologies such as nanofibers, nanobricks, nanosheets, nanospheres, and nanowires have rapidly developed as promising gas-sensing materials to detect NO 2 . However, the main drawbacks of the In 2 O 3 -based NO 2 gas sensor are their incomplete adsorption and desorption equilibrium at higher temperature (>150 °C), namely, that the unsteady-state signal because of insufficient diffusion channels.…”

Section: Introductionmentioning

confidence: 99%

Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Liu

et al. 2021

ACS Appl. Mater. Interfaces

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NO2 gas sensors based on metal oxides under wild conditions are highly demanded yet an incomplete surface reaction and humidity interference on the gas-sensing performance limit their applications. Herein, we report three-dimensional (3D) porous In2O3 microcubes via a simple hydrothermal strategy to produce outstanding NO2 gas-sensing performance: fast equilibrium of the surface reaction at 150 °C and negligible humidity dependence on the NO2 gas sensing at room temperature. The 3D porous In2O3 microcubes with high surface areas, suitable pore sizes, rich oxygen vacancies, and high conductivity are testified. The underlying structural transformation mechanism for 3D porous In2O3 is investigated in detail. The as-made 3D porous In2O3 microcubic gas sensors present excellent gas-sensing performance to 50 ppm NO2 at 150 °C, including a high response value (2329), fast response/recovery time (10/9 s), a low detection limit (10 ppb), long-term stability (60 days), and strong selectivity. Furthermore, they exhibit relatively stable NO2 gas response under humidity variation (20–80%). The NO2 gas mechanism under the interference of water is also clarified.

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Section: Introductionmentioning

confidence: 99%

Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Liu

et al. 2021

ACS Appl. Mater. Interfaces

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“…It can be seen that broad absorption bands of all samples were observed at about 430 nm, and as the hydrogenation time of WO 3 increases, the UV absorbance also increases sequentially, which implies the gradually increasing concentration of oxygen vacancies. , As seen from the inset of the ( ah ν) 2 – h ν graph (Figure S3b), the band gap of the samples was between 2.5 and 2.7 eV, which was consistent with the results reported in the existing literature. , In addition, with the extension of hydrogenation time, the band gap values of hydrogenated WO 3 NSs gradually decreased to 2.5 eV, which was related to the change of the free radical in visible light absorption and the increase in oxygen defects in the hydrogenation process. , As a verification, we performed PL tests of D-WO 3 -1–4 with a 325 nm laser source. In general, the PL peak at 450–650 cm –1 is considered to be directly related to the oxygen defect concentration of the MOS Figure shows the PL spectra of several D-WO 3 NSs, and the oxygen defect concentration of WO 3 NSs increases with the increase in hydrogen treatment time.…”

Section: Resultsmentioning

confidence: 99%

Active W Sites Promoted by Defect Engineering Enhanced C₂H₆S₃ Sensing Performance of WO₃ Nanosheets

Yang

et al. 2022

ACS Sens.

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Defect engineering has received extensive attention as an effective method to tune the gas sensing properties of semiconductor materials. Here, defective WO 3 (D-WO 3 ) nanosheets were obtained by a simple hydrogenation process with a detection limit as low as 5 ppb for dimethyl trisulfide (DMTS) and a response of 2.3 times that of the initial WO 3 nanosheets to 100 ppb DMTS. Importantly, X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the partial loss of oxygen atoms in D-WO 3 nanosheets, and density functional theory calculations found that the W sites near the oxygen defect showed higher adsorption energy for DMTS and transferred more electrons during the gas interaction, indicating that the active W site caused by oxygen atom loss can effectively enhance the reactivity of twodimensional WO 3 nanosheets. Different from the traditional oxygen defect model, this work reveals the positive effect of active metal sites on gas sensing for the first time, which is expected to provide an effective reference for the sensing application of defect engineering in metal oxides.

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“…The calculated specific surface area of 6%Cu-In 2 O 3 nanofibers is 71.6 m 2 /g, which is higher than that of pristine In indicating that the number of oxygen vacancies in the 6%Cu-In 2 O 3 nanofibers is higher than that in the pristine In 2 O 3 nanofibers. The increased oxygen vacancies can provide much more adsorption sites, thus enhancing the sensitivity of the sensor [41,42]. The binding energies of Cu 2p peak (Fig.…”

Section: Structure and Morphologymentioning

confidence: 99%

Electrospun Cu-doped In2O3 hollow nanofibers with enhanced H2S gas sensing performance

et al. 2022

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One-dimensional nanofibers can be transformed into hollow structures with larger specific surface area, which contributes to the enhancement of gas adsorption. We firstly fabricated Cu-doped In2O3 (Cu-In2O3) hollow nanofibers by electrospinning and calcination for detecting H2S. The experimental results show that the Cu doping concentration besides the operating temperature, gas concentration, and relative humidity can greatly affect the H2S sensing performance of the In2O3-based sensors. In particular, the responses of 6%Cu-In2O3 hollow nanofibers are 350.7 and 4201.5 to 50 and 100 ppm H2S at 250 °C, which are over 20 and 140 times higher than those of pristine In2O3 hollow nanofibers, respectively. Moreover, the corresponding sensor exhibits excellent selectivity and good reproducibility towards H2S, and the response of 6%Cu-In2O3 is still 1.5 to 1 ppm H2S. Finally, the gas sensing mechanism of Cu-In2O3 hollow nanofibers is thoroughly discussed, along with the assistance of first-principles calculations. Both the formation of hollow structure and Cu doping contribute to provide more active sites, and meanwhile a little CuO can form p—n heterojunctions with In2O3 and react with H2S, resulting in significant improvement of gas sensing performance. The Cu-In2O3 hollow nanofibers can be tailored for practical application to selectively detect H2S at lower concentrations.

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Sn-doping induced oxygen vacancies on the surface of the In2O3 nanofibers and their promoting effect on sensitive NO2 detection at low temperature

Cited by 62 publications

References 46 publications

Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Active W Sites Promoted by Defect Engineering Enhanced C₂H₆S₃ Sensing Performance of WO₃ Nanosheets

Electrospun Cu-doped In2O3 hollow nanofibers with enhanced H2S gas sensing performance

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Sn-doping induced oxygen vacancies on the surface of the In2O3 nanofibers and their promoting effect on sensitive NO2 detection at low temperature

Cited by 62 publications

References 46 publications

Tunable NH4F-Assisted Synthesis of 3D Porous In2O3 Microcubes for Outstanding NO2 Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Tunable NH4F-Assisted Synthesis of 3D Porous In2O3 Microcubes for Outstanding NO2 Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Active W Sites Promoted by Defect Engineering Enhanced C2H6S3 Sensing Performance of WO3 Nanosheets

Electrospun Cu-doped In2O3 hollow nanofibers with enhanced H2S gas sensing performance

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Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Tunable NH₄F-Assisted Synthesis of 3D Porous In₂O₃ Microcubes for Outstanding NO₂ Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature

Active W Sites Promoted by Defect Engineering Enhanced C₂H₆S₃ Sensing Performance of WO₃ Nanosheets