SiO2@NiO core/ shell nanoparticles as high-performance anode materials: Synthesis and characterizations of structural, optical and magnetic properties

• Synthesis and structural and optical properties of the SiO 2 @ NiO core-shell nanostructures . • The SiO 2 @ NiO nanoparticles have an amorphous structure with NiO shell nanoparticles. • The morphology of core/shell nanoparticles by SEM, shows form of spherical core with a coating of NiO. • VSM showed the soft ferromagnetic for NiO and paramagnetic for the SiO 2 @NiO. In this paper, synthesis and structural and optical properties of the SiO 2 @ NiO core-shell nanostructures were studied. The SiO 2 and NiO nanoparticles and SiO 2 @NiO core/shell nanoparticles were prepared by co-precipitation and chemical reduction method using the two different agents of functionalized silica and non-functionalized silica. The XRD analysis showed that SiO 2 nanoparticles have an amorphous structure and NiO nanoparticles have a cubic structure. The XRD analysis of SiO 2 @NiO core/shell nanoparticles showed the presence of nickel oxide phase and silica amorphous phase as well as a background of silica nanoparticles. The morphology of SiO 2 @NiO core/shell nanoparticles by Scanning Electron Microscopy (SEM), shows form of spherical core with a coating of NiO and it was confirmed by transmission electron microscopy (TEM) analysis. Also, the diameter of these nanoparticles was about 125 ± 5 nm as a halo (shell) of NiO nanoparticles on spherical silica nanoparticles The UV-Vis spectroscopic studies showed that the energy gap of the SiO 2 @NiO core/shell nanoparticles varied in the range of 3.80 – 4.20 eV. The results of the magnetization experiment (VSM) of the samples showed the soft ferromagnetic structure for the nickel oxide nanoparticles and the paramagnetic structure for the SiO 2 @NiO core shell nanoparticles. Finally, the Fourier transform infrared (FTIR) spectrum confirmed the formation of SiO 2 -H, NiO-H and Ni-O bonds in core-shell nanostructures. It can be expected that these nanostructures are suitable as high-performance anode materials in various types of fuel batteries, including lithium batteries.