Interface Optimization of Silicon Oxycarbide Ceramic-Coated Electrodes for Enhanced Electrochemical Performance

Amorphous silicon oxycarbide ceramics derived from Si-based polymeric precursors are promising candidates for electrochemical applications because of their versatility and remarkable chemical stability. This study focuses on optimizing the silicon oxycarbide particle size to enhance adhesion and comparing its adhesion on the two substrate materials- copper foil and CNT buckypaper. Silicon oxycarbide ceramics were synthesized using the polymer precursor route, and graphene nanoplatelets (10 wt.%) were added to these ceramics to enhance their electrical conductivity. Pyrolysed ceramics were subsequently ball-milled to 50 nm, 200 nm and 600 nm particle sizes. Contact angle measurements were conducted to estimate the surface free energy of copper films and CNT bucky paper. A sessile drop technique was employed to measure contact angles, from which interfacial tensions were calculated for different liquid-solid systems. The Owens-Wendt-Rabel-Kaelble (OWRK) method was employed to compare the surface free energy (SFE) of different solid surfaces. The calculated surface free energies for copper films and CNT bucky paper surfaces are 37.98 mN/m and 49.02 mN/m at room temperature, respectively. Our study infers that silicon oxycarbide with a particle size of 600 nm exhibits better adhesion on CNT buckypaper. Additionally, cyclic voltammetry tests were carried out to evaluate the electrochemical performance of synthesized Si-O-C/GNP coated on CNT bucky paper, which served as the working electrode.