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