Synthesis and characterization of silica nanoparticles from sorghum straw (<i>Sorghum bicolor</i> (L.) <i>Moench</i>) and the evaluation of its effect on seed germination of <i>Beta vulgaris</i> (Beetroot)

Abstract

The synthesis of silica nanoparticles (Si-NPS) using the sol-gel method and characterization, as well as their impact on the germination of Beta vulgaris seeds were investigated. Si-NPs were synthesized using sorghum straw, characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy, SEM/Energy Dispersive Spectroscopy, X-ray Spectroscopy (EDS). Assessment of the results carried out on the synthesized Si-NPs revealed the following: FTIR showed absorption bands at 790.20, 1051.10, 1636.30, and 3403.10 cm-1 indicating the presence of Si-H, Si-O-Si, Si-O and Si-OH respectively. XRD analysis showed that the Si-NPs had an average size of 30.46 nm. SEM analysis showed that the Si-NPs were made up of amorphous mesoporous structures. The elemental composition of the sample was found to be 65.33 % Si, 12.77 % O, 11.05 % Al, 5.23 % Fe, 3.42 % C and 2.20 % Na. The result from the germination study demonstrated that as the concentration of Si-NPs increased from (0-8 g/L), the germination rate and vigour index of seeds also increased, with 8 g/L having the highest germinated seedlings. The control which has no Si-NPs recorded the least seedling growth. The study of the germination time also showed that seeds with the highest Si-NPs concentration of 8 g/L, germinated within the least germination period (2 days) when compared with the germination period of the control. This research has shown that increase in concentration of Si-NPs have a positive effect on the germination of Beta vulgaris (Beetroot).