The Synthesis and Characterization of Low-Cost Mesoporous Silica SiO₂ from Local Pumice Rock

Abstract

Pumice is a porous volcanic rock containing a significant proportion of silica and alumina, and which has a low iron content. This natural, silica-rich material attracts wide attention because of its applications in adsorption processes, heterogeneous catalysis and nanotechnology. In this contribution, the white amorphous silica nanoparticles were extracted using an optimized alkaline treatment and an acid-precipitation process using grey pumice powder. The isolated amorphous silica SiO2 was characterized via X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electronic Microscopy (TEM-EDS), N2 adsorption/desorption measurements and simultaneous Thermal Gravimetry/Differential Thermal Analysis (TG/DTA). The obtained results indicated that the nanosilica powder was successfully prepared via the acid-base route with a predominantly amorphous mesoporous structure having a high surface area (422m2/g). The TEM images exhibited relatively homogeneous dispersed nanosilica particles with small sizes about 5–15 nm, in accordance with XRD data. Thermal analysis of the silica powder under air atmosphere showed total mass losses of 6.5%, with endothermic effects corresponding to the removal of water molecules and the OH of silanol groups contained in the material. The investigations performed in this work have indicated that there is great scope for pumice exploitation as a raw material in the production of amorphous silica nanopowder on large scale.

Synthesis and Characterization of Microwave Absorber SiO2by Sol-Gel Methode

“…From the observation, the surface area of SiO 2 was 298.3 m 2 /g. These results were lower than the surface area of SiO 2 generated from Pumice Rock by Asmaa Mourhly et al which reached 422 m 2 /g [15]. This difference is possibly due to the differences in the raw materials used.…”

High‐purity amorphous silica from rice husk: Preparation and characterization

“…In this EDX spectrum, only oxygen (O) and silicon (Si) elements are detected, suggesting that the silica can be high-purity. Previously, a similar EDX spectrum has been reported by Mourhly et al [13] However, the silica in Mourhly's work was extracted from pumice rock. [13] We could not find in the literature any similar EDX result for RH-based silica.…”

“…Previously, a similar EDX spectrum has been reported by Mourhly et al [13] However, the silica in Mourhly's work was extracted from pumice rock. [13] We could not find in the literature any similar EDX result for RH-based silica. Rather, all previously-reported EDX results for RH-based silica show significant presence of undesired elements.…”

A Highly Sensitive Impedimetric DNA Biosensor Based on Hollow Silica Microspheres for Label-Free Determination of E. coli

“…Infrared spectroscopy was used to characterize the features of HSMs before and after the calcination process ( Figure 2b). The FTIR spectra of the HSMs before and after calcination show absorption bands at 1640 cm −1 and 3388 cm −1 , corresponding to a bending vibration of the O-H group (1640 cm −1 ) and hydrogen bonding from the interaction with the silanol group (Si-OH) on the silica surface [22,23]. Before calcination, the absorption bands appeared at 806 cm −1 and 1065 cm −1 , which are assigned to the siloxane symmetry group (Si-O-Si) and siloxane asymmetry streching vibration (Si-O-Si), respectively.…”