Abstract
| Original language | English |
|---|---|
| Journal | Reaction Chemistry & Engineering |
| Volume | 4 |
| Issue number | 12 |
| Pages (from-to) | 2060-2073 |
| Number of pages | 43 |
| ISSN | 2058-9883 |
| DOIs | |
| Publication status | Published - 2019 |
Cite this
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Impact of cation redox chemistry on continuous hydrothermal synthesis of 2D-Ni(Co/Fe) hydroxides. / Rosa, Massimo; Marani, Debora; Perin, Giovanni; Simonsen, Søren Bredmose; Zielke, Philipp; Glisenti, Antonella; Kiebach, Ragnar; Lesch, Andreas; Esposito, Vincenzo.
In: Reaction Chemistry & Engineering, Vol. 4, No. 12, 2019, p. 2060-2073.Research output: Contribution to journal › Journal article › Research › peer-review
TY - JOUR
T1 - Impact of cation redox chemistry on continuous hydrothermal synthesis of 2D-Ni(Co/Fe) hydroxides
AU - Rosa, Massimo
AU - Marani, Debora
AU - Perin, Giovanni
AU - Simonsen, Søren Bredmose
AU - Zielke, Philipp
AU - Glisenti, Antonella
AU - Kiebach, Ragnar
AU - Lesch, Andreas
AU - Esposito, Vincenzo
PY - 2019
Y1 - 2019
N2 - 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 °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 °C) to LDH. Conversely, for the NiFe-hydroxides the transition from LDH (temperatures ≤ 80 °C) to brucite phase (temperatures > 80 °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.
AB - 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 °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 °C) to LDH. Conversely, for the NiFe-hydroxides the transition from LDH (temperatures ≤ 80 °C) to brucite phase (temperatures > 80 °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.
U2 - 10.1039/C9RE00334G
DO - 10.1039/C9RE00334G
M3 - Journal article
VL - 4
SP - 2060
EP - 2073
JO - Reaction Chemistry & Engineering
JF - Reaction Chemistry & Engineering
SN - 2058-9883
IS - 12
ER -