Synthesis, characterization of nickel aluminate nanoparticles by microwave combustion method and their catalytic properties

• Simple route for the preparation of nickel aluminate.
• NiAl2O4 microwave absorbent was invented by a simple method.
• High specific surface area was obtained at low temperature.
• Evaluation of magnetic, optical and catalytic properties.

Microwave combustion method (MCM) is a direct method to synthesize NiAl2O4 nanoparticles and for the first time we report the using of Sesame (Sesame indicum L.) plant extract in the present study. Solutions of metal nitrates and plant extract as a gelling agent are subsequently combusted using microwave. The structure and morphology of NiAl2O4 nanoparticles are investigated by X-ray diffraction (XRD), Fourier transforms infrared spectra (FT-IR), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), high resolution transmission electron microscopy (HR-TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy, Brunauer–Emmett–Teller (BET) analysis and vibrating sample magnetometer (VSM). XRD pattern confirmed the formation of cubic phase NiAl2O4. The formation of NiAl2O4 is also confirmed by FT-IR. The formation of NiAl2O4 nanoparticles is confirmed by HR-SEM and HR-TEM. Furthermore, the microwave combustion leads to the formation of fine particles with uniform morphology. The magnetic properties of the synthesized NiAl2O4 nano and microstructures were investigated by vibrating sample magnetometer (VSM) and their hysteresis loops were obtained at room temperature. Further, NiAl2O4 prepared by MCM using Sesame (S. indicum L.) plant extract is tested for the catalytic activity toward the oxidation of benzyl alcohol.