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

► Glass-like carbon as electrodes, crucibles and separators for fuel cells under acidic condition. ► Acidic treatments with H 2SO 4, HNO 3 and H 2O 2 aq. for the carbon. ►Difference of weight change and surface morphology with each acid. ► Discussion in surface reaction with XPS analysis. Surface oxidation and/or corrosion behavior of glass-like carbons (GLCs) in concentrated H 2SO 4, HNO 3 and H 2O 2 aq. were investigated with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and by weight changes. With GLCs treated in H 2SO 4, formation of sulfur-containing chemical species was observed, with some weight gain. However, no change was observed in morphology. With the samples treated in HNO 3, 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 H 2O 2 aq., rapid weight loss and void formation were observed.