Synthesis of boron nanoparticles by a hybrid “polyol-solvothermal” process using glycerol as reducing agent

Abstract

In this article, a novel hybrid synthesis process called the “polyol-solvothermal process” is presented. This process utilizes a polyol-solvothermal hybrid method under acidic conditions (pH = 1) to obtain amorphous boron nanoparticles with a spherical morphology. The synthesis parameters include different concentrations of metalloid ions (1 and 2 M), glycerol (50% and 80% w/w), and PVP (0.01 g and 0.02 g). To examine the morphology and particle size, surface plasmon resonance (SPR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were employed. The TEM analysis revealed the presence of spherical nanoparticles with an average size of ~5 nm and quasi-spherical microparticles with an average diameter of 3.5 µm. This suggests the presence of microparticles composed of smaller particles, which was confirmed by the surface plasmon resonance (SPR) results. The SPR analysis revealed bands around 275 nm, indicating the presence of boron nanoparticles. The x-ray diffraction (XRD) results show a single peak associated with the formation of amorphous boron. Furthermore, the FT-IR studies identified a peak between 1019 and 1040 cm^-1, which is related to the stretching vibrational bond of CH₂-OH, indicating the decomposition of glycerol into primary alcohols, which acted as reducers. Another band, located at approximately 500 cm^-1and characteristic of the M-O vibrational bond, was associated with the formation of metal nanoparticles.