Surface oxidation and/or corrosion behavior of glass-like carbon in sulfuric and nitric acids, and in aqueous hydrogen peroxide

Surface oxidation and/or corrosion behavior of glass-like carbons (GLCs) in concentrated H2SO4, HNO3 and H2O2aq. were investigated with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and by weight changes. With GLCs treated in H2SO4, formation of sulfur-containing chemical species was observed, with some weight gain. However, no change was observed in morphology. With the samples treated in HNO3, the weight initially increased and, then, decreased. No nitrogen-containing chemical species were observed. Crack formation and scaling off of the upper layers were observed. With the samples treated in H2O2aq., rapid weight loss and void formation were observed.

► Glass-like carbon as electrodes, crucibles and separators for fuel cells under acidic condition.
► Acidic treatments with H2SO4, HNO3 and H2O2aq. for the carbon.
► Difference of weight change and surface morphology with each acid.
► Discussion in surface reaction with XPS analysis.