Study of the structural curvature in Mo2C derived carbons with contrast matched small-angle neutron scattering
| Autor: | Indrek Tallo, Riinu Härmas, Tavo Romann, Jitendra P. Mata, Heisi Kurig, Miriam Koppel, Enn Lust, Kenneth Tuul, Ben Kent, Margarita Russina, Rasmus Palm, Eneli Härk |
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| Rok vydání: | 2021 |
| Předmět: |
Cylindrical geometry
Materials science chemistry.chemical_element 02 engineering and technology General Chemistry Contrast (music) Neutron scattering 010402 general chemistry 021001 nanoscience & nanotechnology Curvature 01 natural sciences Small-angle neutron scattering 0104 chemical sciences chemistry Chemical physics General Materials Science 0210 nano-technology Porosity Mesoporous material Carbon |
| Zdroj: | Carbon. 171:695-703 |
| ISSN: | 0008-6223 |
| Popis: | The influence of the synthesis conditions on the formation of the porous and the graphitic structure of carbon materials was investigated on Mo2C-derived carbon materials synthesized at different temperatures (Tsyn from 700 to 1000 °C). Contrast matched small-angle neutron scattering method was used to obtain explicit information about the pore and pore wall structure of the carbons. It was found that carbons formed at lower Tsyn exhibit prevalently nano-scale cylindrical geometry and an increase in Tsyn promotes the formation of slit-like structures. Additionally, partial contrast matching was used, which effectively made the pore walls wider, enabled to „hide“ the smaller pores, exposing in greater detail the geometries of larger mesopores. The geometry of larger structures (e.g. pores and pore walls) changes from mixed cylindrical and slit-like to completely slit-like with the increase of Tsyn. The observed change of the geometries, expressed by the increase in the dimensionality parameter, that increases from 1.2 to 1.8, empirically correlates with the decrease in the disorder between graphitic layers. Thus, we conclude that the cylindrical structures are caused by the curvature in graphitic layers formed at lower Tsyn (≤800 °C). |
| Databáze: | OpenAIRE |
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