Adsorption Properties of Activated Carbons Prepared from Waste CDs and DVDs

Two sets of activated carbons have been prepared from waste CDs and DVDs by carbonization and subsequent activation with either KOH or CO 2 . The resulting activated carbons had specific surface area in the range of 500–2240 m 2 g –1, total pore volume in the range of 0.18–1.36 cm 3 g –1, volume of micropores and small mesopores ( w < ∼2.9 nm) in the range of 0.17–1.25 cm 3 g –1, and volume of small micropores ( w < ∼1.2 nm) in the range of 0.14–0.71 cm 3 g –1 . Both KOH and CO 2 activation resulted in 5–45-fold improvement in the structural properties, depending on the conditions used. The resulting carbons showed good adsorption properties toward carbon dioxide, hydrogen, and benzene. The best uptakes for these adsorptives were 5.8 mmol g –1 of CO 2 at 0 °C and 800 mmHg, 3.3 mmol g –1 of CO 2 at 25 °C and 850 mmHg, 13.9 mmol g –1 of H 2 at –196 °C and 850 mmHg, and 15.4 mmol g –1 of C 6 H 6 at 20 °C and saturation pressure. The excellent adsorption properties of the prepared carbons render them as potential adsorbents in CO 2 capture and storage, VOCs adsorption/separation, and hydrogen storage.