Activated carbons from the Amazonian biomass andiroba shells applied as a CO2 adsorbent and a cheap semiconductor material

Amazonian andiroba shell was used as a non-expensive, renewable biomass resource to produce a porous activated carbon as a CO2 adsorbent and a cheap supercapacitor material. Activated carbons were prepared by CO2 physical activation of hydrochars obtained from hydrothermal carbon of biomass. The effect of activation times (1 h, 5 h, and 10 h) at 880 & DEG;C on the physical characteristics of the activated carbons was investigated. A significant increase of surface area (from 616 to 1937 m(2)/g) with respect to the activation time was observed. AC AND-5 h showed good microporosity, with the highest adsorption capacity of CO(2 )was obtained as 3.2 mmol/g and 6.1 mmol/g at 25 ? and 0 ? up to 1 bar, respectively. The sample AND-AC-5 h shows a good CO2/N-2 selectivity and fast adsorption kinetics that be easily regenerated with superior cyclic stability after multiple cycles. Moreover, it proved that the photogenerated electrons and holes in wide band gap carbon can be easily transferred into carbon, resulting in a suppressed charge recombination. The best charge transfer processes was received for AC-AND-1 h sample.

Automated summary

In this study, Amazonian andiroba shell was used to produce a porous activated carbon for CO2 adsorption and a cheap supercapacitor material. The results showed that the surface area of the activated carbons increased significantly with longer activation time, and the AC AND-5 h sample exhibited good microporosity and high CO2 adsorption capacity.