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.The authors would like to thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) – Brazil for the financial support (PVE 2014, process number 400714/2014-0). Fabiano G. F. de Paula and Paulo F. R. Ortega also acknowledge CAPES and CNPq for the received scholarships, respectively. Financial support from Ministerio de Economía, Industria y Competitividad (project MAT2016-77114-R) and Principado de Asturias (Fondo Europeo de Desarrollo Regional (GRUPIN 14-118).Peer reviewe