Analysis of the oxidation behavior of neat and Ta-alloyed glass-like carbons heat-treated at 1200 and 3000 °C by nitric, sulfuric and hydrofluoric acid

Surface oxidation and/or corrosion behavior of furan-resin-derived carbons in nitric, sulfuric and hydrofluoric acids were investigated by the relative weight changes and X-ray pohotoelectron spectroscopy (XPS). The behavior of the neat and Ta-alloyed furan-resin-derived carbons heat-treated at 1200 and 3000 °C were compared in this analysis. The weights of the neat specimens heat-treated at 1200 °C obviously decreased after the acidic treatments. The spectroscopic analysis found that oxygen in the internal area as well as on the external surface were increased. The Ta-alloyed specimens heat-treated at 1200 °C after treated by nitric and sulfuric acid have lesser amounts of oxygen in the internal area than the neat specimens. We, therefore, imply in this report that Ta prevents oxygen from penetrating into the depths of the carbons.