Extraction of Silica Nanoparticles from Iraqi Agricultural Waste for Eco-Friendly Technology Applications

Abstract

Bamboo is a widely distributed agricultural waste material, particularly in Iraq, due to its rapid and uncontrolled growth, which can have significant environmental and economic impacts. Silica is a major component of bamboo leaf ash, with reported contents ranging from 75.90% to 82.86%. In this study, a modified precipitation method was employed to extract silica nanoparticles from bamboo leaves. Proximate analysis revealed an ash content of 24.48% and a silica content of 76.226% in bamboo leaf ash. The extraction of silica nanoparticles from bamboo leaf ash under different operating conditions influenced the silica yield and quality. A maximum reported yield of 99.232% was achieved using a 4 N NaOH solution. Fourier-transform infrared (FTIR) spectroscopy identified Si–O–Si, Si–O, and Si–OH bonds. Furthermore, atomic force microscopy (AFM) measurements indicated an average silica nanoparticle diameter of 87.55 nm. The results indicated that pretreatment methods and leaching conditions influenced the structure, size, and quality of the synthesized silica nanoparticles (SiO₂ NPs). Additional characterization techniques, including X-ray fluorescence (XRF), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM), were employed to evaluate the properties and purity of the extracted silica. The synthesized silica nanoparticles have potential applications as reinforcing fillers in composite materials and may also be suitable for applications in the pharmaceutical, food, and nutrition industries, as well as in nanocatalysis.