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

Abstract

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.