Influence of activated charcoal on the structural and morphological characteristics of ceramic based on silicon oxycarbide (SiOC): A promising approach to obtain a new electrochemical sensing platform

Abstract

This study deals with the preparation of ceramic materials based on silicon oxycarbide (SiOC), by pyrolysis of polymeric precursors consisting of poly(methylsiloxane) (PMS) and divinylbenzene (DVB), with or without activated charcoal (AC) as additional carbon source. The precursors were obtained by hydrosilylation reaction catalyzed by Pt(0)-complex at 80:20 and 20:80 (PMS:DVB) molar ratios, containing or not 3 wt.% AC. SiOC-based materials were obtained by pyrolysis at 1000 and 1500 °C, under argon atmosphere, and characterized by FT-IR, Raman, 29Si MAS NMR, XRD, elemental analysis, SEM and HRTEM techniques. The presence of AC in PMS-rich ceramic produced carbon long nanowires, and possibly SiC nanowires. The increase of the temperature induced the phase segregation, with the predominance of SiO2 and/or SiC phases, besides having influence on the crystallization of β-SiC and organization of segregated carbon phase (Cfree), with the formation of multiwall carbon nanotubes (MWCNT). The ceramics containing AC were tested as a new electrochemical sensing platform for the detection of acetaminophen by cyclic voltammetry. Higher peak current and lower over potential for acetaminophen, as compared with glassy carbon electrode, were observed by using the ceramic obtained at 1500 °C containing MWCNT as electrodic material, which clearly indicates the great electrocatalytic effect of material.