Production and Characterization of Amorphous Silica Nanoparticles from Coconut Shell and Coir

Abstract

Silica has been produced from coconut coir and coconut shell because of the economic importance of coconut in India. The wastes are generated and disposed of indiscriminately while several are utilized for the energy source. The ash produced by burning them is usually discarded with a considerable amount of extractable silica present. Therefore, extraction of this silica was done using an environmentally friendly chemical approach to produce silica that could be used in several applications. The wastes were calcined at 700°C in a muffle furnace to get ash, treated with HCl to remove soluble metallic oxides, and after that sol-gelled to obtain silica gel. The gel was then dried at 65°C for 24 hours and characterized using SEM, EDX, FT-IR, and XRD. Silica produced is amorphous with good absorbance potentials. The SEM micrographs show the particles in the Nano size range but with a high level of agglomeration.