Synthesis and Characterization of Amorphous Silica Nanoparticles from Oil Palm Leaf Biomass via Acid and Thermal Treatments
Adikwu Gowon Jacob
Abdulkarim Shehu Salihu
Ojochide Monday Ameh
Aminu Garba Abdullahi
Yusuf Mamman
Abdulazeez Lawal Maigoro
Abstract
This study describes a method of transforming underutilized oil palm leaf biomass into silica. In the present study, a simple method of preparing amorphous silicais reported. The preparation consists of two steps: (1) acid-treatment of oil palm leaf biomass with concentrated HCl, and (2) calcination of the acid-treatedoil palm leaf biomass at 600 ℃. The oil palm leaf biomass, acid-treated oil palm leaf biomass and the resulting silica were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results from the synthesis showed that a silica yield of 28.9% was obtained. FTIRspectroscopy revealed five absorption peaks at 567, 800, 955, 1055, 1633 and 3392 cm‒1 in the spectrum of the heat-treated oil palm leaf biomass which indicates the formation of silica. Also, the peaks at 1445, 2847, 2920 cm‒1 attributed to C-H bonds of –CH2 or ‒CH3 groups in the raw oil palm leaf biomass disappeared after the acid- and thermal-treatments. X-ray diffractogram of the oil palm leaf biomass showed multiple 2θ peaks from 20-55°, typical of crystalline structure, which disappeared and formed a single broad or halo peak centered at 2θ = 22.1⁰ afterthe treatments, with crystallinity indexof 9.43%,confirming the formation of an amorphous silica phase. SEM microgram of the thermal-treated oil palm leaf biomass showed agglomerated particleswith spherical morphology and particlesize ranging from 75-90 nm, supporting the formation of silica nanoparticles. Notably, this study revealed that amorphous silica could be prepared using a simple, energy-efficient method.
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