The shape of the adsorption isotherms gives useful information about the porous structure of the tyre-derived-carbons. Fig.4 ashows a comparison between the isotherms of the original pyrolytic char and the carbon obtained after 1-h activation at 900 8C.
The active carbon predominantly exhibits a type IV isotherm, which is characteristic of mesoporous materials. The initial adsorption capacity at low relative pressures records limited micropore development.
Moreover, an important mesoporous structure is created, as is evidenced by nitrogen adsorption at high relative pressures and by the typical hysteresis loop of mesoporous materials [35].