Controlling the surface chemistry of carbon xerogels using HNO3-hydrothermal oxidation

HNO3-hydrothermal oxidation is used to finely adjust the amount of oxygenated surface groups on a carbon xerogel to a desired degree. The extent of carbon surface functionalization is found to be strongly dependent on the concentration of nitric acid and is described by first order exponential correlations. Significant textural changes are not observed at low concentrations of HNO3, while an increase of the surface area of these materials is observed at high acid concentrations (0.10–0.30 mol l−1) at 473 K.