Phenol adsorption in dilute solution on template-synthesized porous carbons depends on both surface oxygen groups and pore structures. Thermal treatment of porous carbons under nitrogen can markedly facilitate phenol adsorption because of the substantial removal of the oxygen groups. At low phenol concentrations, the surface chemistry of the carbons is of most importance and affects the adsorption behaviors of phenol to a large extent. For porous carbons with a similar surface chemistry, the maximum phenol adsorption capacity increases with the increases in surface area and micropore volume of the porous carbons. The enhancement of phenol adsorption capacity after thermal treatment under nitrogen can be explained by (1) fewer water clusters formed on the carbon surface due to the removal of oxygen groups on carbon surface, (2) the stronger dispersive interactions between the benzene ring of phenol and the carbon basal planes because of the reduction of carboxylic groups and an increase of polyaromatic characters on carbon surface, (3) more carbonyl groups that provide more sites for the donor-accepter interactions, (4) creation of more smaller micropores in pore structure.