A facile synthesis of nitrogen-doped porous carbons from lignocellulose and protein wastes for VOCs sorption.

This paper reported a sustainable method for preparation of N-doped porous carbon from co-hydrothermal carbonization (co-HTC) of lignocellulose (as a carbon skeleton) and sludge protein (as a nitrogen dopant). The HTC pretreatment could improve the yield of porous carbon. Although a low mass ratio (1:1) of biochar and KOH was employed, large specific surface areas of the porous carbons could be achieved. The porous carbon from rice husk (RH) by the HTC (260 °C) combined with the KOH activation (750 °C) had a largest BET surface area up to 1396.5 m/g. Meanwhile, its adsorption capacity on toluene could reach 394.2 mg/g. It was attributed to its large specific surface area and hierachical porous structure with higher meso-porosity. The porous carbons with N-doping also improved the adsorption capacity. Furthermore, thermal desorption at around 300 °C had a high potential for regeneration of the saturated porous carbons.