Page 59 - Synthesis of Functional Nanoparticles Using an Atmospheric Pressure Microplasma Process - LiangLiang Lin

Iron Oxide Nanoparticles Synthesis and Mechanism Study - a Proof-of-Concept Model Study
helps to enhance cyclopentadienyl rings dissociation degree.
3.3.3 SEM and EDX Analysis
For the general overview of the products surface morphology, SEM imaging was applied. Figure 3.4 shows SEM images of the products synthesized at plasma power of 1.05 W (a) and 2.27 W (b). It seems that lower power results in more uniform morphology. The deposits produced at 1.05 W microdischarge power appear to be snowflake-like or fibril-like fractal structures, with no round particles. However, at higher power one can observe particles with different shapes, such as snowflake-like, fibril-like, felt-like or round. This can be explained by the temperature increase with dissipated power, which helps to “melt” the snowflake-like or fibril-like particles to form round shape products. Meanwhile, the temperature gradient is also larger at higher power, leading to particles with various shapes.
Figure 3.4 SEM images of materials obtained at plasma power of 1.05 W (a) and 2.27 W (b)
To examine chemical composition of prepared nanoparticles, EDX measurements of particles produced at 1.05 W were carried out. The EDX mappings of Fe, C and O as well as the corresponding SEM image are shown in Figure 3.5. O is detected all over the area, with a quite uniform spatial distribution. It implies nanoparticles are uniformly oxidized. Besides, Overall EDX spectrum shows that no unexpected impurities exist in products. Peaks corresponding to C and O are always present. C peaks either come from precursor dissociation or from the carbon tape, while O peaks are due to oxidation of iron nanoparticles either during the reaction process or during the transfer process.
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