Green synthesis of amorphous silica nanoparticles (SiO2NPs) from sugarcane bagasse ash by sol-gel method

Sugarcane bagasse ash was utilized as a silica source in the sol-gel polymeric method used to produce amorphous silica nanoparticles (SiO 2 NPs). Sugarcane production process generates a huge amount of bagasse, an agricultural waste, which may constitute an environmental hazard if not properly managed. Due to sugarcane bagasse being a natural source of silica, this study produced silica nanoparticles as an alternate purpose for this waste. The present research uses L-cysteine hydrochloride monohydrate acid and citric acid to extract silica from sugarcane bagasse ash, with it being the first to utilize L-cysteine hydrochloride monohydrate in the sol-gel polymeric synthesis of silica. In order to study the extracted silica, XRD, FTIR, XRF, PIXE, SEM/EDS, TEM, and TGA were used to characterize the resulting silica xerogel in order to identify its elemental composition, surface morphology, functional groups, crystalline phases, thermal stability, and porosity. The purification techniques studied made it possible to produce silica nanoparticles with varying degrees of purity, a range of 67.25–94.58 wt% of silica xerogels were produced. Amorphous SiO 2 nanoparticles were produced, with an average size of about 11–21 nm. The produced silica xerogel demonstrated porous network topologies with a high specific surface area and mesopore volume of 199.19, 469.09, 523.89 m 2 /g and 0.77, 0.64, 0.71 cm 3 /g using L-cysteine hydrochloride monohydrate, hydrochloric acid and citric acid respectively, according to the data. These materials, combined with morphological characteristics—large specific surface and pore volume—allow them to be used in a variety of technical domains, including biomedical, electronics, and optical.