Engineering chemical pathways for phase-tuned nanocrystalline iron oxides in microwave-assisted solvothermal synthesis

Kandoor, S and Dhar, S and Kumar, L and Arackal, S and Sai, R and Shivashankar, SA (2022) Engineering chemical pathways for phase-tuned nanocrystalline iron oxides in microwave-assisted solvothermal synthesis. In: Physical Chemistry Chemical Physics, 24 (46).

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Abstract

In microwave-assisted solvothermal synthesis (MASS) of nanocrystalline iron oxides, we have analysed chemical pathways to explore the role played by the temperature and heating rate in deciding the phases and crystallographic orientations. We have achieved control over synthesis parameters by using tailored mixtures of solvents. These kinetically controlled pathways are engineered by suitably mixing high microwave dielectric loss solvents - ethanol and water, with 1-decanol. We propose two new pathways, and combinations of different pathways, to explain the observed phases in reactions between metal acetylacetonates and these solvents, using Fe(acac)3 as a representative. The proposed pathways also explain the changes in the local geometry from octahedral to square pyramidal, enroute to tetrahedral in oxides. Mixing solvents to alter tan δ is shown to provide an energy-efficient way to control the specific geometry of grown phases. The results demonstrate new ways of analysing and tuning the synthesis of complex oxides in pure and mixed solvents, under microwave irradiation.

Item Type:	Journal Article
Publication:	Physical Chemistry Chemical Physics
Publisher:	Royal Society of Chemistry
Additional Information:	The copyright for this article belongs to Royal Society of Chemistry.
Keywords:	Dielectric losses; Energy efficiency; Microwave irradiation; Mixing; Nanocrystals; Organic solvents, Chemical pathways; Crystallographic orientations; High microwave; Kinetically controlled; Microwave-assisted; Mixture of solvents; Nanocrystallines; Phase orientation; Solvothermal synthesis; Synthesis parameters, Iron oxides
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	04 Jan 2023 05:05
Last Modified:	04 Jan 2023 05:05
URI:	https://eprints.iisc.ac.in/id/eprint/78688

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