Water in porous carbons

We present an overview of progress in understanding the behavior of water in porous carbons at the molecular level. We survey experimental investigations, semi-empirical approaches, and simulation studies. Experimental work faces a number of challenges: the determination of the distribution of carbon microcrystal sizes, the densities and species of surface groups, the topological nature of the connected pore structure, and pore size distributions. The lack of experimental characterization, together with the uncertainty in the intermolecular potentials involved, has thwarted molecular simulation efforts thus far. A concerted approach that links experimental and simulation efforts appears promising in gaining a better understanding of the behavior of water in porous carbons. Experimental results could aid in the development of realistic carbon models and improve the intermolecular potentials used in the simulation studies. In a complementary fashion, molecular simulation could help improve characterization methods of both the carbon structure and the surface chemistry.