Investigation on the performance of phenyl-rich silicon oxycarbide (SiCO) ceramics as electrode material for voltammetric detection of carbendazim

Abstract

This paper demonstrated the feasibility of phenyl-rich oxycarbide (SiCO) ceramics as electrode materials in voltammetric measures of carbendazim using cyclic voltammetry. Ceramics were prepared from pyrolysis of poly(dimethylsiloxane-co-diphenyl-siloxane) divinyl terminated, crosslinked with divinylbenzene, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and in the absence of crosslinking agent, using argon atmosphere up to 1500 °C during 1, 3, and 5 h. Silicon carbide (SiC) crystallites and graphitic carbon domains were produced in the non-crystalline matrices and the phase crystallization was improved as the annealing time increased, mainly in the presence of organic crosslinker. SiCO-based electrode materials were used as a paste (ceramic and mineral oil in 80:20 wt.% proportion), and carbendazim’s voltammetric behavior was compared to commercial glassy carbon electrode (GCE). The electrochemical performance of ceramic electrodes showed a dependence on both polymer chemistry and annealing time, in which organic crosslinker-derived SiCO at 3h annealing displayed the best voltammetric response for carbendazim when compared to other ceramics and commercial GCE. Larger semiconductive SiC crystallites, better graphitization of residual carbon phase, lower charge transfer resistance and higher porosity developed into ceramics derived from organic crosslinker played a crucial role on electrochemical performance of SiCO materials. Apart from the improved performance for carbendazim detection, the unmodified produced ceramics, and their direct use as electrode materials, bring substantial advantages for the preparation of sensors avoiding time-consuming and skills to properly prepare, as usually observed in the modified electrodes.