Porosity adjustment of activated carbon: theory, approaches and practice

The adsorption capacity of activated carbons (ACs) is primary dependent on their porosity and functional groups on their surfaces, and in some cases the applications of ACs are eventually determined by their porous structure. Therefore, it is of great importance to research and develop methods for the preparation of ACs with a specific porosity which could meet the demands of their suggested application fields. A literature survey of the characterization of porous structure, the relationship between the porosity of ACs and their specifications, as well as principles and approaches to adjust their porosity is given in this paper with the aims of (a) further understanding the significance of porosity in ACs, (b) elucidating mechanisms to regulate the porosity of ACs and (c) to thus make specifications for the preparation of ACs.