Unravelling the growth mechanism of the co-precipitation of iron oxide nanoparticles with the aid of synchrotron X-Ray diffraction in solution

Abstract

The formation mechanism of iron oxide nanoparticles reveals an initial segregation into ferrihydrite seeds and a Fe2+ rich growth reservoir.

Influence of channel height on mixing efficiency and synthesis of iron oxide nanoparticles using droplet-based microfluidics

“…nucleation followed by particle growth in co-precipitation reactions. 16 Fast homogenization in micro-uidic devices is challenging, which is given by low values of Reynolds number (Re < 1) and laminar character of a ow, and mixing is only governed by molecular diffusion. 17 Just as a droplet formation, enhancement of a droplet internal mixing can be achieved passively 18 or actively 6 using external energy, e.g.…”

“Nano-garden cultivation” for electrocatalysis: controlled synthesis of Nature-inspired hierarchical nanostructures

“…Though the coprecipitation approach has recently allowed precise control of the formation of complex micrometer-scale shapes with amazing beauty, downsizing the shape to the nanometer scale is yet impossible. 18,36,38,39 In this work, via coupling the hydrothermal and electrodeposition synthesis approaches under different reaction conditions, we managed to design and prepare a number of Co(OH) 2based nano-architectures that resemble various items in a garden ("soil", "ake", "sprout", "grass", "ower" and "leaf"). Such patterns can be fully phosphidated, forming CoP structures.…”

A Modular Millifluidic Platform for the Synthesis of Iron Oxide Nanoparticles with Control over Dissolved Gas and Flow Configuration

“…For the most common aqueous synthesis of IONPs, the so called co-precipitation method, the pH of a solution of ferrous and ferric ions is increased typically via the addition of a base, causing the precipitation of the nanoparticles [19,20]. This can happen either slowly by continuous addition over minutes or hours, or fast, i.e., via a one-time injection resulting in an abrupt pH increase.…”

“…This can happen either slowly by continuous addition over minutes or hours, or fast, i.e., via a one-time injection resulting in an abrupt pH increase. These commonly used fast co-precipitation syntheses result in the immediate formation of iron-containing particles after mixing the precursor and base solution, and depending on the synthesis conditions, these intermediate precipitates evolve towards the magnetite/maghemite phase [19][20][21]. The rapidity of such co-precipitation syntheses can limit the reproducibility [22] when using conventional batch reactors, where fast mixing is hard to achieve and precipitation kinetics might vary due to spatial pH variations.…”