Preparation and pore properties of char materials derived from wood chips of Japanese cedar (Sugi) and cherry wood (Sakura) immersed in surfactant solutions

Porous char materials were prepared by immersing wood chips of Japanese cedar ( Sugi ) and cherry wood ( Sakura ) in surfactant solutions followed by heat treatment at 1000 °C. The XRD patterns exhibited peaks for the amorphous carbon of the char materials derived from the wood and peaks corresponding to the sodium salts generated from the pyrolysis of the surfactants in which the wood was immersed to prepare the char materials. The surface areas (458–598 m 2 g⁻¹) and micropore volumes (0.19–0.24 mL g⁻¹) of the char materials from cedar immersed in surfactant solutions were slightly larger than those of the untreated char materials (393 m 2 g⁻¹ and 0.16 mL g⁻¹). In contrast, the values (776–823 m 2 g⁻¹ and 0.31–0.34 mL g⁻¹) of the char materials from cherry wood immersed in surfactants were significantly larger than those of the untreated char materials (103 m 2 g⁻¹ and 0.05 mL g⁻¹). Indeed, the values of char materials from surfactant-immersed cherry wood were comparable to those from iodine-treated sawtooth oaks (706 m 2 g⁻¹ and 0.24 mL g⁻¹), NaOH-activated coconut shell (783 m 2 g⁻¹ and ca . 0.36 mL g⁻¹) or H 3 PO 4 -activated coconut shell ( ca . 600 m 2 g⁻¹). The pore-size distribution curves of the char materials from cherry wood immersed in surfactants indicated micropores with sizes less than 1 nm. These results suggest that the pore-related properties of the char materials were improved as a result of activation by a small amount of surfactant. The char materials from cherry wood immersed in surfactants could be suitable for applications based on adsorption and purification materials requiring only surfactant treatment without any other specific or hazardous pre- and/or post-treatments. • Porous char materials were prepared from Japanese cedar and cherry wood. • Chemical activation was induced by surfactants containing sodium and/or phosphate. • Surface areas, pore volumes, and pore-size distributions were measured. • Pore-related properties of chars from surfactant-immersed cherry wood were improved.