Michaud M, Peukert W, Distaso M (2023)
Publication Type: Journal article
Publication year: 2023
Book Volume: 427
Article Number: 118677
DOI: 10.1016/j.powtec.2023.118677
Size and shape control of nanoparticles is fundamental to tune their material properties and to identify structure property functions. Herein, the shape of goethite (α-FeOOH) particles is varied from needle to spindle upon sodium carbonate modulation. Our in-depth study sheds light on the formation path of goethite particles by in situ monitoring the pH, the dissolved oxygen concentration and Raman spectroscopy in the presence and in the absence of sodium carbonate. The pH evolution indicates two distinct plateaus, at 7–6.5, and 6–6.3, respectively: the time when the dissolved oxygen concentration vanishes is correlated with the time required to oxidize Fe(II) to Fe(III). Raman spectroscopy enabled the identification of the intermediate phases green rust at 500 cm−1 and siderite at 1080 cm−1. Their formation and depletion was correlated with the kinetics of goethite formation. The evolution of the olation reaction is monitored through the bending vibration of water at 1640 cm−1. Finally, goethite particles are characterized ex situ via X-ray diffraction to assess the crystalline phase, scanning electron microscopy (SEM) for evaluating the size and shape of particles and transmission electron microscopy (TEM) for the analysis of the three-dimensional arrangement of self-assembled layers. The evaluation of reflectance spectra with CIELAB color metrics show that goethite spindles have enhanced color properties in comparison to the needle-shaped particles.
APA:
Michaud, M., Peukert, W., & Distaso, M. (2023). An in situ study to shed light on the formation of goethite spindles by pseudomorphic transformation of intermediate phases. Powder Technology, 427. https://dx.doi.org/10.1016/j.powtec.2023.118677
MLA:
Michaud, Mark, Wolfgang Peukert, and Monica Distaso. "An in situ study to shed light on the formation of goethite spindles by pseudomorphic transformation of intermediate phases." Powder Technology 427 (2023).
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