Porous carbon monoliths from ice-NaOH templated dissolved cellulose

A simple and environmentally friendly route for the transformation of cellulose to porous carbon monoliths was developed. The procedure is based on freezing the cellulose solution in aqueous NaOH (−10 °C), followed by a direct regeneration of the frozen material in an ethanol bath and washing the alkaline with water. After atmospheric drying, the obtained cellulose monoliths composed mainly of cellulose II polymorph showed considerable macroporosity related to an ice-templating effect. During carbonization (500–900 °C, carbon yield >20%) the macroporosity (≈1–100 µm) was preserved together with monolithic character. The resulting monolithic carbons also showed significant microporosity, with micropore volume up to 0.25 cm3/g, depending on carbonization temperature.