Resource Recovery from Maize Biomass for the Synthesis of SiO2 Nanoparticles and Crystallographic Analysis for Possible Applications

Abstract

This study demonstrates the successful recovery of silicon dioxide (SiO₂) nanoparticles from maize biomass, highlighting their structural characteristics and environmental implications. Maize waste samples ere obtained as the stocks of the plants after harvesting and employed as precursors for the synthesis of SiO₂ nanoparticles using the sol gel method. The produced nanoparticles were analysed for their crystalline properties using XRD machine. The X-ray diffraction (XRD) analysis indicated some structural features, including deviations in diffraction angles (2θ) from standard Quartz (SiO₂), ranging from -0.01° to +0.14°. At 30.28°, a positive deviation of +0.14° indicated lattice contraction, while a negative deviation of -0.01° at 41.80° suggested lattice expansion. These shifts reflect lattice strain, defects, and quantum confinement effects at the nanoscale. Calculated d-spacing values, derived using Bragg’s equation, further emphasized these structural alterations, with deviations ranging from -0.12 Å to +0.01 Å. Notably, d-spacing at 30.28° (2.95 Å) showed compression by -0.12 Å compared to the reference value (3.35 Å), while at 41.80° (2.16 Å), a slight expansion of +0.01 Å was observed. Phase analysis confirmed the crystalline SiO₂ structure, with close alignment to standard Quartz (JCPDS Card Number 46-1045). The lattice parameters, calculated as a = 8.07 Å and c = 3.83 Å, showed minimal deviation from standard Quartz values (a = 8.14 Å and c = 3.83 Å), with a minor contraction of -0.7 Å for lattice constant a. Texture coefficient (TC) analysis revealed preferential crystallographic orientations, with high TC values at 30.28° (1.1176) and 35.20° (1.0649), indicating enhanced electrical conductivity and surface reactivity along these planes. Conversely, weaker diffraction at 20.24° (TC = 0.5098) reflected structural imperfections and non-uniform alignment. The structural features observed in the synthesized SiO₂ nanoparticles underscore their suitability for diverse applications. High surface reactivity, arising from nanoscale effects and lattice strain, supports their use in environmental remediation, such as water purification and heavy metal adsorption. The preferential crystallographic orientations enhance catalytic activity, while the structural integrity and stability ensure effectiveness in soil stabilization and nutrient delivery in agriculture. Additionally, the nanoparticles exhibit potential for incorporation into optoelectronic devices and green construction materials, improving functionality and sustainability. The untilization of maize biomass in this study reveals a sustainable method for SiO₂ nanoparticle synthesis and also addresses environmental concerns by valorizing agricultural waste. The results emphasize the need to control synthesis parameters to optimize properties for targeted applications, presenting a significant step toward sustainable nanotechnology solutions with positive environmental impacts.