Preparation and properties of heteroatom-doped bacterial cellulose-derived carbonaceous materials

In this study, nitrogen and sulfur heteroatom-doped bacterial cellulose (BC) derived carbon materials have been prepared by a simple, feasible, and environmentally friendly approach that can be easily scaled up for various applications. In the first step, BC was successfully fabricated with chitosan and carrageenan compounds by a layer-by-layer assembly technique without using any template. The resulting composites were then subjected to carbonization to enrich carbon content of the material while incorporation of nitrogen and sulfur heteroatoms into the carbon structure without applying a chemical treatment. A wide variety of BC-derived N- and S-doped carbons were prepared using chitosan and different types of carrageenan precursors. The results showed that the dominant heteroatom on the BC composites was dependent on the last heteroatom precursor used in the layer-by-layer assembly process. The skeleton of the BC composites did not collapse after carbonization and the resulting materials were highly dense and porous having ribbon-like carbon structures. The use of iota-carrageenan as a sulfur precursor with combination of chitosan as a nitrogen precursor resulted in better heteroatom-doped carbons as compared to other carrageenan compounds studied. Synthesized carbons showed great potential as catalyst for hydrothermal conversion of glucose to hydrogen as tested in this study.