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Synthesis of carbon xerogel and modification of its surface by various oxidative treatments are explored. Organic gel was synthesized by following the conventional sol-gel approach using formaldehyde and resorcinol. The wet gel was dried under subcritical condition and then carbonized, leading to carbon xerogel. Subsequently, the carbon xerogel was subjected to surface activation by means of oxidative treatment with nitric acid, sulphuric acid as well as aerial oxidation. Surface acid/base properties of the carbon xerogel have been strongly altered by treatments with nitric acid as well as with sulphuric acid. On the other hand, total surface area and pore volume have been significantly modified by air activation.

Influence of synthesis variables on the textural properties of mesoporous carbon xerogels is studied. Variables explored in synthesizing mesoporous carbon xerogels (CX) are: (i) initial formaldehyde/resorcinol molar ratio in preparing the sol, (ii) pH of sol-gel processing, (iii) temperature of gelling and subsequent curing of the gel, and (iv) mode of subcritical drying of the wet gel. Making of sol having formaldehyde/resorcinol molar ratio little higher than 2 and sol-gel processing at pH around 6 resulted in carbon xerogel with wide pores. Curing of gel at higher temperature resulted in carbon xerogel with narrower pores. Drying of the organic gel after exchanging water with low boiling organic solvent was highly beneficial in obtaining carbon xerogel with wider pores along with larger mesoporous area.