Study on effect of structure and surface/ physical characteristics of a silicon oxycarbide by hydrofluoric acid etching

ABSTRACT

In this study, polymer-derived porous silicon oxycarbide (SiOC) ceramic was synthesised by considering various polymer precursors such as polymethylhydrosiloxane, polydimethylsiloxane and cyclic 2,4,6,8-tetramethyl-2,4,6,8tetravinlycyclotetrasiloxane in various proportions. The pyrolysis temperature of 1000°C was fixed to obtain the amorphous nature of SiOC, which is considered to be favourable for use in anode material for the Li ion batteries. Further, to enhance surface properties viz porosity, pore volume of these pyrolysed SiOC ceramics, hydro fluoric acid etching was performed. In order to establish effect of etching on the SiOC ceramic, various structural and physical/surface characterisations such as Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, Brunauer–Emmet–Teller and Barrett–Joyner–Halenda analysis were conducted. The results showed that specific surface area improved from 164 to 474 m² g⁻¹ before and after etching, respectively.

KEYWORDS:

• Silicon oxycarbide
• porous ceramics
• specific surface area

Acknowledgments

We would like to acknowledge Central Analytical Laboratory (CAL) facility at BITS Pilani, Hyderabad Campus for giving access to the various characterization facilities used for carrying out this work.

Disclosure statement

No potential conflict of interest was reported by the authors.