The surface of activated carbon, like other carbon materials can be fluoralkylated by treatment with (per)fluoropolyether peroxide in a liquid phase, or with a wide range of fluoroorganic substances by CVD-method. Such materials combine high hydrophobicity and chemical stability with electrical and thermal conductivity and can be used as electrode material for supercapacitors Sulfonic acid functional groups can be attached to activated carbon to give "starbons" which can be used to selectively catalyze the esterification of fatty acids.[50] Formation of such activated carbons from halogenated precursors gives a more effective catalyst which is thought to be a result of remaining halogens improving stability.