Laser pyrolysis synthesis of Sn–Fe–N@polycarbosilazane nanocomposites, characterization and evaluation as energy storage materials

摘要: We report the single-step synthesis of novel tin-based core–carbosilazane shell nano-composites using laser pyrolysis technique. Controlled NH3 flows were used to entrain vapors volatile precursors: Sn(CH3)4 (TMT) and Fe(CO)5 injected through center for core [Si(CH3)3]2NH (HMDS) annular nozzle shell. Both HMDS plays also role absorbers IR radiation. The obtained nanoparticles shown polydispersity with sizes from 5 up around 120 nm, having spheroidal crystalline core—disordered morphology as confirmed by transmission electron microscopy images, where short amorphous nanofibers observed. dominant phase β-Sn (having mean crystallite size between 22 29 nm) minor tin-iron intermetallic nitride phases identified X-ray diffraction. Infrared spectra show presence Si–N Si–C bonds, pointing a carbosilazane composition shells, accompanied Si–O bonds due partial oxidation after air exposure. Three different samples keeping constant Sn Fe precursors diminishing HDMS flow, together corresponding flows. Preliminary tests these materials anodes Li-ion battery showed an initial discharge capacity near 800 mAg/h which decreased 300 mAh/g 20 cycles sample highest content.