Mesoporous carbon from SiO2-C nanocomposite prepared with industrial raw materials: Synthesis and characterization

• Published in: Diamond and related materials Vol. 126; p. 109047
• Main Authors: Benito, Damián E., Lombardi, M. Bárbara, Scian, Alberto N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-06-2022; Elsevier BV
• Subjects: Activated carbon; Carbon; Composite; Drinking water; Ethoxylated silica precursor; Formaldehyde resins; Fourier transforms; Graphene; Infrared spectroscopy; Nanocomposites; NMR; Nuclear magnetic resonance; Phenol formaldehyde resin; Pore size; Pore size distribution; Porosity; Precursors; Raman spectroscopy; Raw materials; Silicon dioxide; SiO2-C system; Sol-gel; Sol-gel processes; Spectrum analysis; Synthesis; Tetraethyl orthosilicate; Wastewater treatment; Water purification; Phenol formaldehyde resin; Composite; Ethoxylated silica precursor; SiO2-C system; Sol-gel; Activated carbon
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2022.109047

A SiO2-C composite (SC) was prepared via sol-gel method using industrial raw materials: commercial partially hydrolysed tetraethyl orthosilicate as an ethoxylated silica precursor (ESP) and phenolic-formaldehyde resin as a carbon precursor. The synthesized composite, constituted by a silica network cross-linked with a carbon network, resulted in a material with a sharp pore size distribution (pore size diameter ~ 32 nm) and a high specific surface area (~350 m2/g). In a subsequent step, it was possible to isolate each network: Carbon (C) and Silica (S). In this work, the composite synthesis, and the isolation paths to obtain the individual structures are described. In addition, the composite and the isolated structures were mineralogically and structurally characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (laser of 785 nm = 1.58 eV) (RS), nuclear magnetic resonance (NMR) and thermogravimetric analyses (TGA). The textural characterization was performed by nitrogen adsorption (SBET), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM-EDS). The three materials exhibited properties suitable for applications such as catalysis, immobilization of bioactive molecules and dyes, drug delivery, among others. In particular, the carbonaceous network had a pseudo graphene structure and microdomains of high activity, which would enhance its use as a low-cost material in new green technologies for wastewater treatment and drinking water purification.
Highlihgts•A SiO2-C ceramic composite was obtained from industrial raw materials by sol-gel and heat treatment.•To achieve a reproducible and homogeneous material two operational variables were controlled.•The obtained composite was chemically treated, the independent phases of SiO2 and C were isolated.•The resulting C shows a pesudo-graphitic structure and other interesting textural properties [Display omitted]