Shape-controlled multi-porous carbon with hierarchical micro–meso-macro pores synthesized by flash heating of wood biomass

We developed a simple synthesis of shape-controlled porous carbon materials that combine a high porosity of over 80% with a high Brunauer–Emmett–Teller surface area of 670 m 2/g. The synthesis involves flash heating of sawdust and subsequent low-temperature heat treatment (380 °C). Flash heating changed the morphology of the sawdust to the specific three-dimensional microtexture of amorphous carbon, and the subsequent heat treatment dramatically increased the surface area of the shape-controlled porous carbon materials. The products consisted of cross-linked carbon beams containing surface micro-pores (pore size < 2 nm) and meso-pores (5 nm < pore size < 50 nm). Moreover, macro-pores (5 μm < pore size < 50 μm) were found between the cross-linked carbon beams.