Enhanced H2S sensing characteristics of Au modified Fe2O3 thin films

Balouria, Vishal; Ramgir, Niranjan S.; Singh, Ajay; Debnath, A.K.; Mahajan, Aman; Bedi, R. K.; Aswal, D. K.; Gupta, S. K.

doi:10.1016/j.snb.2015.04.113

Cited by 79 publications

(17 citation statements)

References 36 publications

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“…For this reason, the sensitivity and selectivity of the CuO sensor material must be improved. Several methods to enhance the sensing properties of these materials are known, including forming core/shell structures [16], decoration with noble metals [17], structure modification [18], doping [19], and the decoration of the CuO surface with metal oxide semiconductor (MOS) nanoparticles [20]. Fe 2 O 3 , an n-type MOS, is also used for H 2 S gas sensing.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of a low-concentration H2S gas sensor using CuO nanorods decorated with Fe2O3 nanoparticles

et al. 2016

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Section: Introductionmentioning

confidence: 99%

Fabrication of a low-concentration H2S gas sensor using CuO nanorods decorated with Fe2O3 nanoparticles

et al. 2016

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“…Thus, the iron sulphides will be formed on the surface of the α-Fe 2 O 3 nanowires, which will also increase the conductivity of the sensor because of the low band gap intrinsic characteristic of such iron sulphides. However, as reported by Singh [33], the reaction (1) plays a more predominant role in the sensing process.…”

Section: Resultsmentioning

confidence: 82%

“…The results demonstrated that the sensor based on 2.33% Au modified α-Fe 2 O 3 thin films exhibited the highest H 2 S response. The optimum operating temperature of which was 250 °C with a response of 6.4 to 10 ppm H 2 S. It also found that the response time of this sensor was very long (27 min) [33]. Despite these progress have been made, as can be seen in Table 1, it can be found that there are still some limitations to meet the requirements of practical application, including relatively low sensitivity, high detection limit, and high operating temperature.…”

Section: Introductionmentioning

confidence: 99%

Controllable Synthesis of Zn-Doped α-Fe2O3 Nanowires for H2S Sensing

et al. 2019

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One-dimensional Zn-doped α-Fe2O3 nanowires have been controllably synthesized by using the pure pyrite as the source of Fe element through a two-step synthesis route, including the preparation of Fe source solution by a leaching process and the thermal conversion of the precursor solution into α-Fe2O3 nanowires by the hydrothermal and calcination process. The microstructure, morphology, and surface composition of the obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was found that the formation process of α-Fe2O3 is significantly influenced by the introduction of Zn2+. The gas sensing measurements indicated that the sensor based on 1% Zn-doped α-Fe2O3 nanowires showed excellent H2S sensing properties at the optimum operating temperature of 175 °C. Notably, the sensor showed a low H2S detection limit of 50 ppb with a sensor response of 1.5. Such high-performance sensing would be ascribed to the one-dimensional structure and high specific surface area of the prepared 1% Zn-doped α-Fe2O3 nanowires, which can not only provide a large number of surface active sites for the adsorption and reaction of the oxygen and H2S molecules, but also facilitate the diffusion of the gas molecules towards the entire sensing materials.

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“…While the catalytic dissociation of H2S due to the Au surface modification led to a tremendous enhancement of the sensitivity of ZnO NWs, the strong affinity between Au and S may also be the reason for an ongoing and irreversible contamination of the catalyst as well. The strong chemical affinity between Au and S presumably led to a reactive interaction between both elements [32,39,40]: H2S(g) + Au(s) → AuS(s) + H2(g).…”

Section: Discussionmentioning

confidence: 99%

Highly Sensitive H2S Sensing with Gold and Platinum Surface-Modified ZnO Nanowire ChemFETs

Kaiser

Ceja

Huber

et al. 2020

The 1st International Electronic Conference on Biosensors

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In this work, we investigate the catalytic effects of gold (Au) and platinum (Pt) nanoparticle layer deposition on highly sensitive zinc oxide (ZnO) nanowires (NWs) used for selective H2S detection in the sub-ppm region. Optimum quality pristine ZnO NWs were grown by high temperature chemical vapor deposition (CVD) in the vapor liquid solid growth (VLS) mode on silicon with a thin Au layer acting as a growth catalyst. The surface of pristine ZnO NWs was modified by systematic magnetron sputtering of discontinuous Au and Pt layers of 0–5 nm thickness. Resistive gas sensors based on the gas sensing mechanism of a chemical field effect transistor (ChemFET) with open gate, which is formed by hundreds of parallel aligned pristine Au-modified or Pt-modified ZnO NWs, were measured toward H2S diluted in dry nitrogen (N2) or in dry synthetic air at room temperature. Gas sensing results showed a largely improved response due to the catalytic effects of metal deposition on the ZnO NW surface. Controlled application of ZnO NW growth under optimized conditions and metal catalyst deposition showed a clear response enhancement toward 1 ppm H2S from the initial 20% achieved with pristine ZnO to over 5000% with ZnO NWs covered by 5 nm of Au, and, hence, significantly lower than the limit of detection.

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Enhanced H2S sensing characteristics of Au modified Fe2O3 thin films

Cited by 79 publications

References 36 publications

Fabrication of a low-concentration H2S gas sensor using CuO nanorods decorated with Fe2O3 nanoparticles

Fabrication of a low-concentration H2S gas sensor using CuO nanorods decorated with Fe2O3 nanoparticles

Controllable Synthesis of Zn-Doped α-Fe2O3 Nanowires for H2S Sensing

Highly Sensitive H2S Sensing with Gold and Platinum Surface-Modified ZnO Nanowire ChemFETs

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