High value activated carbons from waste polystyrene foams

Activated carbons (AC) with excellent textural properties have been obtained for the first time from waste polystyrene foam (PF), without any previous treatment, following a simple and conventional two-step procedure (formation of char followed by chemical activation). Even considering that the PF is not a graphitizable material, the best AC produced from this precursor has a very high BET surface area larger than 2700 m2 g−1 and a pore volume of 1.2 cm2 g−1, with a significant contribution of small mesopores. As a consequence, this AC reveals a surprising capacity to adsorption of relatively large molecules and a high specific capacitance when applied as a supercapacitor electrode. The maximum amount of adsorbed methylene blue obtained by batch equilibrium experiments are greater than 1 g g−1. In the context of the technical difficulties and low economic return of the reuse and recycling of waste PF, this work offers a strategic destination for this environmentally unfriendly residue.