Report
Impact of cation redox chemistry on continuous hydrothermal synthesis of 2D-Ni(Co/Fe) hydroxides
| العنوان: | Impact of cation redox chemistry on continuous hydrothermal synthesis of 2D-Ni(Co/Fe) hydroxides |
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| المؤلفون: | Rosa, Massimo, Marani, Debora, Perin, Giovanni, Simonsen, Søren Bredmose, Zielke, Philipp, Glisenti, Antonella, Kiebach, Ragnar, Lesch, Andreas, Esposito, Vincenzo |
| سنة النشر: | 2019 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Materials Science |
| الوصف: | Continuous hydrothermal flow synthesis (CHFS) is a facile, upscalable and cost-efficient synthetic method enabling the nanostructuring of advanced functional materials in steady conditions, i.e. not in batch synthesis. In this paper, we use CHFS to crystallize NiCo- and NiFe-hydroxides in water solution with 2D nanofeatures. By tuning the synthetic parameters, we disclose the key role of the cation redox chemistry in the transition between two competitive phases: from 2D-nanoplatelets of brucite to layered double hydroxides (LDH). For controlling the precipitation of different Ni, Fe, Co-hydroxide phases, we propose the combined use of an oxidizing (H2O2) and a complexing (NH3) agent. At temperatures as low as 80 {\deg}C, the presence of H2O2 and a low concentration of NH3 favour the Ni2+/Co3+ over Ni2+/Co2+ oxidation states, shifting the product structure from brucite phase (temperatures > 80 {\deg}C) to LDH. Conversely, for the NiFe-hydroxides the transition from LDH (temperatures < 80 {\deg}C) to brucite phase (temperatures > 80 {\deg}C) is controlled by the reaction temperature only. Due to the high stability of Fe3+, the synthesis of NiFe products by CHFS does not require oxidizing and complexing agents, resulting in a robust process for large-scale production. Comment: Tables and Figures at the end of the manuscript |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1039/C9RE00334G |
| URL الوصول: | http://arxiv.org/abs/1910.05047 |
| رقم الانضمام: | edsarx.1910.05047 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1039/C9RE00334G |
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