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Ion beam-induced deposition (IBID) using Pt(CO)2Cl2and Pt(CO)2Br2as precursors has been studied with ultrahigh-vacuum (UHV) surface science techniques to provide insights into the elementary reaction steps involved in deposition, complemented by analysis of deposits formed under steady-state conditions. X-ray photoelectron spectroscopy (XPS) and mass spectrometry data from monolayer thick films of Pt(CO)2Cl2and Pt(CO)2Br2exposed to 3 keV Ar+, He+, and H2+ions indicate that deposition is initiated by the desorption of both CO ligands, a process ascribed to momentum transfer from the incident ion to adsorbed precursor molecules. This precursor decomposition step is accompanied by a decrease in the oxidation state of the Pt(II) atoms and, in IBID, represents the elementary reaction step that converts the molecular precursor into an involatile PtX2species. Upon further ion irradiation these PtCl2or PtBr2species experience ion-induced sputtering. The difference between halogen and Pt sputter rates leads to a critical ion dose at which only Pt remains in the film. A comparison of the different ion/precursor combinations studied revealed that this sequence of elementary reaction steps is invariant, although the rates of CO desorption and subsequent physical sputtering were greatest for the heaviest (Ar+) ions. The ability of IBID to produce pure Pt films was confirmed by AES and XPS analysis of thin film deposits created by Ar+/Pt(CO)2Cl2, demonstrating the ability of data acquired from fundamental UHV surface science studies to provide insights that can be used to better understand the interactions between ions and precursors during IBID from inorganic precursors.
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Cobalt phosphide (Co 2 P) encapsulated in nitrogen-rich hollow carbon nanocages with fast rate potassium ion storage
We synthesized Co 2 P nanoparticle encapsulated N-doped carbon nanocages through one-step carbonization–phosphidation of ZIF-67. As potassium ion battery (KIB, PIB) anodes, the Co 2 P@NCCs display state-of-the-art electrochemical performance, including the most favorable fast charge characteristics reported. The single-nanometer thick carbon cage yields rapid solid-state K-ion diffusion and prevents aggregation/pulverization of 40 nm cobalt phosphide.
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- Award ID(s):
- 1911905
- PAR ID:
- 10295267
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 56
- Issue:
- 94
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 14889 to 14892
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d0cc07123d
