Water adsorbate mediated accumulation gas sensing at hydrogenated diamond surfaces

Beer, Sebastian; Helwig, Andreas; Müller, Gerhard; Garrido, José Antonio; Stutzmann, M.

doi:10.1016/j.snb.2013.02.072

Cited by 17 publications

(12 citation statements)

References 21 publications

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“…When water was removed (by evacuation and heating), the water solvated nitrate converted back to oxide-coordinated nitrate. Existence of such mechanisms on oxide surfaces, including that of Al 2 O 3 [36,37,39] and on diamond surfaces [40] have been confirmed by recent studies. It is conceivable that such a mechanism exists under our experimental conditions where the NO 3 adsorbed on the SWCNT-polymer is first converted to solvated nitrate ions on alumina surface in high humidity (∼60% used here) as observed on the oxide surfaces.…”

Section: Resultsmentioning

confidence: 60%

SWCNT-aminopolymer composites on mesoporous alumina for fast, room-temperature detection of ultra-low concentrations of NO2 by mediation of water vapour

Randeniya

Bendavid

Martin

et al. 2015

Sensors and Actuators B: Chemical

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Section: Resultsmentioning

confidence: 60%

SWCNT-aminopolymer composites on mesoporous alumina for fast, room-temperature detection of ultra-low concentrations of NO2 by mediation of water vapour

Randeniya

Bendavid

Martin

et al. 2015

Sensors and Actuators B: Chemical

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“…The gases that could increase the H 3 O + concentration ion after dissolution into water could surely increase the surface conductivity of the hydrogenated diamond film. This may be the root explanation for the high surface conductivity of hydrogenated diamond films when exposed to gases such as NO 2 and O 3 [22,23], as well as the immutability of the high surface resistance of the hydrogenated diamond film when exposed to gases like CO 2 [24]. Thus, based on the calculation results in this work, sensors sensitive to various gases that increase H 3 O + ion concentration after dissolving into water could be developed.…”

Section: Research Articlementioning

confidence: 71%

Geometries and electronic structures of the hydrogenated diamond (100) surface upon exposure to active ions: A first principles study

Liu

Chen

et al. 2015

Front. Phys.

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To elucidate the effects of physisorbed active ions on the geometries and electronic structures of hydrogenated diamond films, models of HCO − 3 , H 3 O + , and OH − ions physisorbed on hydrogenated diamond (100) surfaces were constructed. Density functional theory was used to calculate the geometries, adsorption energies, and partial density of states. The results showed that the geometries of the hydrogenated diamond (100) surfaces all changed to different degrees after ion adsorption. Among them, the H 3 O + ion affected the geometry of the hydrogenated diamond (100) surfaces the most. This is well consistent with the results of the calculated adsorption energies, which indicated that a strong electrostatic attraction occurs between the hydrogenated diamond (100) surface and H 3 O + ions. In addition, electrons transfer significantly from the hydrogenated diamond (100) surface to the adsorbed H 3 O + ion, which induces a downward shift in the HOMO and LUMO energy levels of the H 3 O + ion. However, for active ions like OH − and HCO − 3 , no dramatic change appears for the electronic structures of the adsorbed ions.

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“…The effect was found to be absent in free‐standing SWCNT films 20. Further, Beer et al21 have described recently the humidity dependence of the adsorption and desorption of reactive gases by the water layers on hydrogenated diamond surfaces. At low humidity, the water layer on the surface accumulates gases leading to a sensor response.…”

Section: Introductionmentioning

confidence: 95%

Harnessing the Influence of Reactive Edges and Defects of Graphene Substrates for Achieving Complete Cycle of Room‐Temperature Molecular Sensing

Randeniya

Shi

Barnard

et al. 2013

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Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide. Annealing at high temperatures, or exposure to strong ultraviolet light under vacuum, is employed to facilitate desorption of these gases. In this article, the molecules adsorbed on graphene nanoflakes and on chemically derived graphene-nanomesh flakes are displaced rapidly at room temperature in air by the use of gaseous polar molecules such as water and ethanol. The mechanism for desorption is proposed to arise from the electrostatic forces exerted by the polar molecules, which decouples the overlap between substrate defect states, molecule states, and graphene states near the Fermi level. Using chemiresistors prepared from water-based dispersions of single-layer graphene on mesoporous alumina membranes, the study further shows that the edges of the graphene flakes (showing p-type responses to NO₂ and NH₃) and the edges of graphene nanomesh structures (showing n-type responses to NO₂ and NH₃) have enhanced sensitivity. The measured responses towards gases are comparable to or better than those which have been obtained using devices that are more sophisticated. The higher sensitivity and rapid regeneration of the sensor at room temperature provides a clear advancement towards practical molecule detection using graphene-based materials.

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Water adsorbate mediated accumulation gas sensing at hydrogenated diamond surfaces

Cited by 17 publications

References 21 publications

SWCNT-aminopolymer composites on mesoporous alumina for fast, room-temperature detection of ultra-low concentrations of NO2 by mediation of water vapour

SWCNT-aminopolymer composites on mesoporous alumina for fast, room-temperature detection of ultra-low concentrations of NO2 by mediation of water vapour

Geometries and electronic structures of the hydrogenated diamond (100) surface upon exposure to active ions: A first principles study

Harnessing the Influence of Reactive Edges and Defects of Graphene Substrates for Achieving Complete Cycle of Room‐Temperature Molecular Sensing

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