Extraction and Physicochemical Characterization of Highly-pure Amorphous Silica Nanoparticles from Locally Available Dunes Sand

Abstract

This study synthesized highly pure silica nanoparticles from the northeast Algerian Sahara dunes sand as a low-cost silica source using a simple and environmentally friendly method. The silica nanoparticles were extracted using a sodium silicate solution as a precursor without employing any additive agents. The extracted silica’s crystalline structure, chemical composition, chemical bonding, microstructure, elemental analysis, thermal analysis, and optical characteristics were investigated. The X-ray diffraction patterns demonstrate the amorphous nature of the extracted silica. Furthermore, the X-ray fluorescence spectroscopy (XRF) and energy dispersive X-ray (EDX) results prove the high purity of the extracted silica (99% SiO 2 ). However, the Fourier-transform infrared spectroscopy (FTIR) results corroborate the presence of silanol and siloxane groups. According to the SEM image analysis, the produced silica has an average particle size in the range of nanometers. Thermal analysis (TGA/DTA) exhibited the high thermal stability of the silica, and the optical band gap energy for silica nanoparticles was determined to be 3.75 eV. Therefore, dunes sand is an alternative source for developing high-purity silica nanoparticles, which have great potential for advanced material applications.

Mineralogical, physicochemical and thermal investigations of Taibet and Tendla sands material from the Northern Algerian Sahara

“…Additionally, oxidation of potential organic materials may occur between 200 and 400 °C (Mikhailova et al, 2022). The weight loss noticed between 530 and 740 °C was strongly linked to the calcium carbonate concentration (Meftah et al, 2023), which exceeded 0.8 % for the T1 sand sample and 2.7 % for the T2 sample. The DTA spectrum of both sand samples shows three endothermic peaks at 105, 574, and 700 °C, as well as one exothermic peak at 886 °C for T2 sand and 1014 °C appear for T1 sand.…”

“…Desert sand contains grains ranging in size from 0.0625 to 2 mm with a typical chemical composition of SiO2 (<90 wt%), Al2O3(<16 wt%), and CaO (<20 wt%), Fe2O3, MgO, TiO2, K2O, and Na2O. Furthermore, desert sand is one of the most promising materials for producing highly pure quartz (silicon dioxide), amorphous silica, as well as Silicon (Meftah and Hani, 2022;Meftah et al, 2023). Radwan et al (2021) showed that Arabian desert sands have the potential to be used as a thermal energy storage medium and solar absorber material.…”

Synthesis and characterization of silica xerogel and aerogel from rice husk ash and pulverized beach sand via sol-gel route

“…The calculated density of the rice husk xerogel was 3.31 g/cm 3 and that of aerogel was 2.86 g/cm 3 , while those of the beach sand xerogel and aerogel were 2.88 g/cm 3 and 2.68 g/cm 3 , respectively, using the crystallographic open data (COD). The variation in the density was due to the different drying techniques employed.The aerogel is lighter than the xerogel because the supercritical extraction method aided the replacement of the liquid component of the alcogel by air.…”

“…where ρ represents density in g/cm 3 and d m is the crystallite diameter in nanometers. The substitution of the respective values of the density and crystallite diameters of the xerogel and aerogel yielded the specific surface area values of 122 m 2 /g and 145 m 2 /g for the xerogel and aerogel, respectively, for the rice husk, which shows an increment of 16 %.…”

“…Silica gels were originally prepared from various solgel precursors like tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS) and polyethoxydisiloxane (PEDS), which are considered expensive and toxic in recent times [3]. Recent scientific efforts are geared towards sourcing for cheaper, safer 1 and readily available natural silica precursors like rice husk and beach sand for the synthesis of nanosilica gels.…”