• Advances in nano research
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• v.17 no.5
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• pp.463-475
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• 2024

Biogenic potassium silicate (K₂SiO₃) NPs were synthesized from the biomasses of walnut shell (w-K₂Si), pinewood stem (p-K₂SiO₃), and sugarcane bagasse (s-K₂SiO₃) by ambient fiery and KOH-assisted thermal process. The crystallite size (D) of w-K₂SiO₃, p-K₂SiO₃, and s-K₂SiO₃ NPs were determined to be 73 nm, 53 nm and 47 nm using Debye-Scherrer's formula. The varied strain of all samples was observed in the 0.284 to 0.301 range. Microstructure showed the cubical geometry with an irregular grain size of K₂SiO₃ NPs, while the SAED pattern confirmed the polycrystalline nature. The E_g of w-K₂SiO₃, p-K₂SiO₃, and s-K₂SiO₃ NPs was determined from Tauc's plot to be 3.66 eV, 3.75 eV, and 3.78 eV, which are closely matched to be 3.78 eV, 3.88 eV, and 3.79 eV estimated from the XPS core-level analysis. The antibacterial activity of w-K₂SiO₃, p-K₂SiO₃, and sK₂SiO₃ NPs was investigated against E. coli and S. aureus bacteria. Compared to K₂SiO₃ NPs, the s-K₂SiO₃ were found to be highly toxic against E. coli and S. aureus and completely inhibited the growth of both organisms within 6 h. The findings represent the novel low-cost development of K₂SiO₃ NPs with potent antibacterial activities.