| 1. |
- Diklic, Natasa P., et al.
(författare)
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Sodium storage via single epoxy group on graphene - The role of surface doping
- 2019
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Ingår i: Electrochimica Acta. - : Elsevier. - 0013-4686 .- 1873-3859. ; 297, s. 523-528
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Tidskriftsartikel (refereegranskat)abstract
- Due to its unique physical and chemical properties, graphene is being considered as a promising material for energy conversion and storage applications. Introduction of functional groups and dopants on/in graphene is a useful strategy for tuning its properties. In order to fully exploit its potential, atomic-level understanding of its interaction with species of importance for such applications is required. We present a DFT study of the interaction of sodium atoms with epoxy-graphene and analyze how this interaction is affected upon doping with boron and nitrogen. We demonstrate how the dopants, combined with oxygen-containing groups alter the reactivity of graphene towards Na. Dopants act as attractors of epoxy groups, enhancing the sodium adsorption on doped oxygen-functionalized graphene when compared to the case of non-doped epoxy-graphene. Furthermore, by considering thermodynamics of the Na interaction with doped epoxy-graphene it has been concluded that such materials are good candidates for Na storage applications. Therefore, we suggest that controlled oxidation of doped carbon materials could lead to the development of advanced anode materials for rechargeable Na-ion batteries.
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| 3. |
- Pašti, Igor, et al.
(författare)
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Atomically Thin Metal Films on Foreign Substrates : From Lattice Mismatch to Electrocatalytic Activity
- 2019
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Ingår i: ACS Catalysis. - : AMER CHEMICAL SOC. - 2155-5435. ; 9:4, s. 3467-3481
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Tidskriftsartikel (refereegranskat)abstract
- Electrocatalytic properties of materials are governed by the electronic structure, stability, and reactivity of the surface layer which is exposed to the electrolyte. Over the years, different strategies have been developed to tailor electrocatalyst surfaces but also to reduce the cost of these materials, which is the bottleneck for any practical application. When a very thin metallic layer, intended to serve as an electrocatalyst, is placed over a substrate, its configuration is influenced by the structure of the substrate due to lattice mismatch, while the electronic structure is affected due to the strain and the electronic effects of the support. This results in altered bonding within the electrocatalyst layer and the modification of its electronic properties when compared to the pure phase. In this contribution, we address the possibilities of theoretical prediction of surface properties of atomically thin electrocatalyst films formed over different substrates, focusing on the metal side of the electrified interface. While all these properties can be calculated quite easily using modern computational techniques (but used with care), most often based on density functional theory, we also address an attractive, fast screening possibility to estimate the properties of monometallic and multimetallic overlayers using small sets of calculations on model systems. We discuss how lattice mismatch between a substrate and an overlayer can be used to predict the properties of electrocatalytic films, limitations of such approach, and a possibility of deploying of large databases which enable rapid prescreening of different support/overlayer systems for various electrocatalytic applications.
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