Reactive porous composites for chromium() reduction applications based on Fe/carbon obtained from post-consumer PET and iron oxide

By using post-consumer PET waste and iron oxide (Fe 2 O 3 ), novel porous magnetic Fe/carbon composites for environmental applications have been obtained by a very simple process. XRD, Mössbauer, TG/MS, SEM, BET and Raman analyses have indicated that molten PET containing dispersed Fe 2 O 3 particles decomposes in the 500-1000 °C range to produce a carbon matrix with developed micro and mesoporosities and surface areas of 136-260 m 2 g −1 , with simultaneous reduction of Fe 3+ to iron phases whose composition depended on the decomposition temperature: (i) reactive Fe 2+ phases, FeOOH, Fe 3 O 4 (magnetite) and FeO (wüstite) for the composites obtained at 500-600 °C and (ii) Fe 0 and Fe 3 C for those obtained at higher temperatures. Investigation of these composites for the reduction of aqueous chromium( vi ) showed high activities for the materials obtained at 500 and 600 °C, which is discussed in terms of the phase composition and presence of carbon surface oxygen groups for the adsorption of Cr 3+ . By using post-consumer PET waste and iron oxide (Fe 2 O 3 ), novel porous magnetic Fe/carbon composites for environmental applications have been obtained by a very simple process.