Native oxidation of ultra high purity Cu bulk and thin films

Iijima, Junichi; Lim, Joo Won; Hong, Sang Hwui; Suzuki, Shigeru; Mimura, Kouji; Isshiki, Minoru

doi:10.1016/j.apsusc.2006.05.063

Cited by 135 publications

(128 citation statements)

References 21 publications

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“…The literature reports metallic Cu with a characteristic peak in the range of 918.2 to 918.6 eV; Cu 2 O has a reported peak between 916.0 and 916.4 eV, and the peak for the CuO standard increases from 917.6 to 917.8 eV. [49][50][51][52][53][54][55] The acid-treated Cu sheet resulted in spectra similar to those previously reported in the literature for air-oxidized metallic Cu. 54,55 This oxidized layer was reported to be in the size range of 1.6 to 2.7 nm.…”

Section: Structural Characterizationsupporting

confidence: 76%

“…The XPS spectra of the Cu 2p region are very challenging to interpret because the metallic state of Cu and Cu(I) have statistically similar binding energy values ( Figure S7a). [49][50][51][52][53][54][55] Hence, the X-ray generated Auger spectra were recorded in the Cu L 3 M 45 M 45 region, and the results are presented in Figure 7a. The literature reports metallic Cu with a characteristic peak in the range of 918.2 to 918.6 eV; Cu 2 O has a reported peak between 916.0 and 916.4 eV, and the peak for the CuO standard increases from 917.6 to 917.8 eV.…”

Section: Structural Characterizationmentioning

confidence: 99%

“…54,55 This oxidized layer was reported to be in the size range of 1.6 to 2.7 nm. 55 For the OD-Cu electrode after the 400 °C heat treatment ("OD-Cu before"), the Auger spectrum exhibited a broad peak at 917.7 eV, indicating the presence of Cu(II) in the surface as CuO. After performing the CO 2 reduction experiment with the OD-Cu electrode ("OD-Cu after"), the Auger spectrum was similar to Cu 2 O with a peak at 916.4 eV, together with the subsequent shoulder at 918.5 eV correlating well with the kinetic energy characteristic of metallic Cu.…”

Section: Structural Characterizationmentioning

confidence: 99%

“…This geometry is followed (0.23 eV higher in energy) by that obtained by replacing one Cu at the corner of the icosahedron structure, Figure 8b. Moving the substitutional Sn atom inside the Cu 55 NP results in clearly less stable geometries. In fact, replacing a Cu in the internal shell (an icosahedron with 12 equivalent atoms) is clearly disfavored (2.31 eV higher than the shell-edge geometry), and moving the Sn atom at the center of the Cu 55 NP, Figure 8d, results highest in energy (2.93 eV higher than the best position).…”

Section: Structural Characterizationmentioning

confidence: 99%

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Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO

et al. 2016

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ABSTRACT. We report a selective and stable electrocatalyst utilizing non-noble metals consisting of Cu and Sn for the efficient and selective reduction of CO 2 to CO over a wide potential range. The bimetallic electrode was prepared through the electrodeposition of Sn species on the surface of oxide-derived copper (OD-Cu). The Cu surface, when decorated with an optimal amount of Sn, resulted in a Faradaic efficiency (FE) for CO greater than 90% and a current density of −1.0 mA cm −2 at −0.6 V vs. RHE, compared to the CO FE of 63% and −2.1 mA cm −2 for OD-Cu. Excess Sn on the surface caused H 2 evolution with a decreased current density. X-ray diffraction (XRD) suggests the formation of Cu-Sn alloy. Auger electron spectroscopy of the sample surface exhibits zero-valent Cu and Sn after the electrodeposition step. Density functional theory (DFT) calculations show that replacing a single Cu atom with a Sn atom leaves the d-band orbitals mostly unperturbed, signifying no dramatic shifts in the bulk electronic structure. However, the Sn atom discomposes the multi-fold sites on pure Cu, Page 1 of 37 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 disfavoring the adsorption of H and leaving the adsorption of CO relatively unperturbed. Our catalytic results along with DFT calculations indicate that the presence of Sn on reduced OD-Cu diminishes the hydrogenation capability-i.e., the selectivity towards H 2 and HCOOH-while hardly affecting the CO productivity. While the pristine monometallic surfaces (both Cu and Sn) fail to selectively reduce CO 2 , the Cu-Sn bimetallic electrocatalyst generates a surface that inhibits adsorbed H*, resulting in improved CO FE. This study presents a strategy to provide a low-cost non-noble metals that can be utilized as a highly selective electrocatalyst for the efficient aqueous reduction of CO 2 . ACS Paragon Plus Environment ACS Catalysis

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Section: Structural Characterizationsupporting

confidence: 76%

Section: Structural Characterizationmentioning

confidence: 99%

Section: Structural Characterizationmentioning

confidence: 99%

Section: Structural Characterizationmentioning

confidence: 99%

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Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO

et al. 2016

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“…Ayse Turak replied: The graphene-Cu bond is expected to be very weak. Yet, graphene is widely reported as a passivation layer, [1][2][3][4] which is also supported by the visual observation in our work of contrast in regions protected by graphene versus those unprotected. However, Zhou et al 5 did show that over the long term, Toshiaki Enoki said: The interaction between graphene and Cu substrate is weak, while other substrates such as Ni and Pd have stronger interactions with graphene.…”

supporting

confidence: 88%

Synthesis in gas and liquid phase: general discussion

Davies¹,

Papakonstantinou²,

Martı́n³

et al. 2014

Faraday Discuss.

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Passivating Polycrystalline Copper with an Ultrathin Samarium Layer

Abrahamczyk,

Walker,

Han

et al. 2024

Adv Eng Mater

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We report how a layer of samarium (Sm) with a thickness equivalent to ∼ 2 atoms (0.8 nm) deposited by thermal evaporation is remarkably effective at passivating polycrystalline copper (Cu) towards oxidation in ambient air. To monitor the rate of Cu oxidation in real time, slab‐like Cu films with a thickness of 9 nm were fabricated on glass modified with a layer of 3‐mercaptopropyl silatrane, which immobilises condensing Cu atoms by reaction with the thiol moiety, promoting slab‐like film formation at very low thickness. Upon exposure to ambient air the rate of increase in electrical resistance due to reaction with oxygen and water is slowed by more than an order of magnitude when the Cu film is capped with the ultra‐thin Sm layer. After 1 year the resistance increases by ∼30% as compared to ∼190% for Cu films without an ultra‐thin Sm layer. Photoelectron spectroscopy, atomic force microscopy and Kelvin probe measurements shed light on the underlying mechanism of passivation. Additionally, the ultra‐thin Sm layer is greatly lowering the work function of polycrystalline Cu films making this approach attractive for applications requiring a low work function electrode with high stability in air.This article is protected by copyright. All rights reserved.

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Native oxidation of ultra high purity Cu bulk and thin films

Cited by 135 publications

References 21 publications

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO

Synthesis in gas and liquid phase: general discussion

Passivating Polycrystalline Copper with an Ultrathin Samarium Layer

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Native oxidation of ultra high purity Cu bulk and thin films

Cited by 135 publications

References 21 publications

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO2 to CO

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO2 to CO

Synthesis in gas and liquid phase: general discussion

Passivating Polycrystalline Copper with an Ultrathin Samarium Layer

Contact Info

Product

Resources

About

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO

Cu–Sn Bimetallic Catalyst for Selective Aqueous Electroreduction of CO₂ to CO