Silica nanoparticles from coir pith synthesized by acidic sol-gel method improve germination economics

Abstract

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (n Si). The synthesized silica nanoparticles (n Si) were characterized by ultraviolet–visible (UV–Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of then Si composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks forn Si and confirmed the formation of an amorphous nature. The average size ofn Si obtained is 18 nm. The surface charge and stability ofn Si were analyzed by using the dynamic light scattering (DLS) and thus revealed that then Si samples have a negative charge (−20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using then Si. The results revealed that the application ofn Si enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenicn Si before mass production and use of agricultural applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.