排序方式: 共有19条查询结果,搜索用时 15 毫秒
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Marco Favaro Silvia Leonardi Carlos Valero‐Vidal Silvia Nappini Marianne Hanzlik Stefano Agnoli Julia Kunze‐Liebhuser Gaetano Granozzi 《Advanced Materials Interfaces》2015,2(5)
Anodic production of self‐organized titania nanotubes (TNTs) in an electrolyte enriched with graphene oxide quantum dots (GOQDs) is reported. The TNT‐GOQD composites grown under these conditions show in‐situ carbon doping, leading to the formation of anatase TiO2 domains and to the reduction to substoichiometric oxide (TiOx) and TiC. Surface science and electrochemical techniques are used in synergy to reveal that graphitic carbon is incorporated into TiO2 upon anodic nanotube growth promoting the formation of oxygen vacancies and thus TiO2 reduction. Upon annealing in ultrahigh vacuum, titanium oxycarbide (TiOxCy) is formed at temperatures ≥400 °C, where the material changes from a semiconductor to a semimetal. At the solid/liquid interface, the apparent electron donor density increases from as‐grown TNTs to as‐grown TNT‐GOQD composites due to the carbon doping, and the conductivity increases further with annealing temperature due to the increasing concentration of coordinatively unsaturated C atoms, crystallinity, and TiO2 reduction. The materials synthesized and characterized in this study find application in different areas ranging from visible light photocatalysis and photo‐electrochemistry to use as Li‐ion battery anodes and electrocatalyst supports, because it is possible to gradually tune the density of states below the Fermi level, which can be referred to as band‐gap engineering. 相似文献
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Sanjaya D. Senanayake Jaime Evans Stefano Agnoli Laura Barrio Tsung-Liang Chen Jan Hrbek Jos�� A. Rodriguez 《Topics in Catalysis》2011,54(1-4):34-41
X-ray and ultraviolet photoelectron spectroscopies were used to study the interaction of Ni atoms with CeO2(111) surfaces. Upon adsorption on CeO2(111) at 300 K, nickel remains in a metallic state. Heating to elevated temperatures (500?C800 K) leads to partial reduction of the ceria substrate with the formation of Ni2+ species that exists as NiO and/or Ce1?xNixO2?y. Interactions of nickel with the oxide substrate significantly reduce the density of occupied Ni 3d states near the Fermi level. The results of core-level photoemission and near-edge X-ray absorption fine structure point to weakly bound CO species on CeO2(111) which are clearly distinguishable from the formation of chemisorbed carbonates. In the presence of Ni, a stronger interaction is observed with chemisorption of CO on the admetal. When the Ni is in contact with Ce+3 cations, CO dissociates on the surface at 300 K forming NiCx compounds that may be involved in the formation of CH4 at higher temperatures. At medium and large Ni coverages (>0.3 ML), the Ni/CeO2(111) surfaces are able to catalyze the production of methane from CO and H2, with an activity slightly higher than that of Ni(100) or Ni(111). On the other hand, at small coverages of Ni (<0.3 ML), the Ni/CeO2(111) surfaces exhibit a very low activity for CO methanation but are very good catalysts for the water?Cgas shift reaction. 相似文献
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Formation of a Quasi‐Free‐Standing Single Layer of Graphene and Hexagonal Boron Nitride on Pt(111) by a Single Molecular Precursor 下载免费PDF全文
Silvia Nappini Igor Píš Tevfik Onur Menteş Alessandro Sala Mattia Cattelan Stefano Agnoli Federica Bondino Elena Magnano 《Advanced functional materials》2016,26(7):1120-1126
It is shown that on Pt(111) it is possible to prepare hexagonal boron nitride (h‐BN) and graphene (G) in‐plane heterojunctions from a single molecular precursor, by thermal decomposition of dimethylamine borane (DMAB). Photoemission, near‐edge X‐ray absorption spectroscopy, low energy electron microscopy, and temperature programmed desorption measurements indicate that the layer fully covers the Pt(111) surface. Evidence of in‐plane layer continuity and weak interaction with Pt substrate has been established. The findings demonstrate that dehydrogenation and pyrolitic decomposition of DMAB is an efficient and easy method for obtaining a continuous almost freestanding layer mostly made of G, h‐BN with only a low percentage (<3%) of impurities (B and N‐doped G domains or C‐doped h‐BN or boron carbonitride, BCN at the boundaries) in the same 2D sheet on a metal substrate, such as Pt(111), paving the way for the advancement of next‐generation G‐like‐based electronics and novel spintronic devices. 相似文献
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Zongge Li Danni Wang Huifang Li Mang Ma Ying Zhang Zifeng Yan Stefano Agnoli Guoxin Zhang Xiaoming Sun 《Nano Research》2022,15(3):1715-1724
Single-atom metal-incorporated carbon nanomaterials(CMs)have shown great potential towards broad catalytic applications.In this work,we show that N-doped porous... 相似文献
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