Transition metal nanoparticles enclosed in carbon nanocages: microscopic images and X-Ray diffraction pattern

Image "Precursors" shows the dried crystals of Ni, Co and Fe precursors for synthesis of nanoparticles in carbon nanocages. Its preparation is described in related research article. SEM images present Ni, Co and Fe nanoparticles enclosed in carbon nanocages (CNCs). Sythesis is made at different temperatures between 500 °C and 850 °C during 10 min. The Ni@ CNCs formed at 500, 550 and 600 °C are seen as small white dots of ~10 nm. However, at 700 and 850 °C, the particle size is increased to ~50-100 nm. Image sequence for Ni shows rapid change of thermolysis rate with temperature. Also, the SEM images of Ni, Co and Fe synthesized at 600 °C is given. The Ni@CNCs and Co@CNCs seen as white dots are similar in size while the size of Fe@CNCs varies from few to a hundred nanometers. Table and image "XRD_FeSPN_in_CNC" shows the XRD pattern of Fe nanoparticles encapsulated in CNCs synthesized at 600 °C. It shows the presence of different phases, metallic α-Fe (red), F2O3 (blue) and Fe3C (green). Table gives the numerical data for these peaks and intensities for α-Fe, Fe2O3 and Fe3C correspondingly.