Chitin-Derived Mesoporous, Nitrogen-Containing Carbon for Heavy-Metal Removal and Styrene Epoxidation

The production of a series of mesoporous, nitrogen-containing (N-containing) carbon materials directly from pure chitin by means of carbonization at different temperatures under template-free conditions is reported. Thermogravimetric analysis combined with infrared spectroscopy was applied to follow the temperature-dependent chemical events during the carbonization process, thereby shedding light on the automated pore formation mechanism. The physicochemical properties of the N-containing carbon materials have been extensively investigated, which provided guidance and rational understanding of the application of these materials. It was found that the N-containing carbon materials obtained at lower temperatures (400-600 degrees C) were enriched with amine, amide, and pyrrolic functionalities, which enables their very high efficiency as adsorbents to remove toxic heavy metals, such as Cr-VI, Hg-II, and Pd-II, from water. In contrast, N-containing carbon materials prepared at higher temperatures (800-1000 degrees C) were enriched with graphitic N, which exhibited excellent catalytic activity in the epoxidation of styrene.