Hydroxyl-Enriched Core/Shell Carbon Nanotubes for Catalytic Hydrolysis of Regenerated Cellulose to Glucose

A hydroxyl-enriched core/shell structured carbon nanotube (CNT/C-OH) is prepared by the method of hydrothermal carbonization (HTC) as a catalytic accelerator to induce highly efficient hydrolysis of regenerated cellulose to glucose. By use of sonication with high sound intensity, the carbon source (namely glucose) is homogeneously dispersed with CNT to form a colloid. Accordingly, a high-quality CNT/C-OH with a hydroxyl-enriched coating layer is produced in the following HTC. The oxygen mass content of the shell is up to 16.38%. A great deal of hydroxyl groups contribute to the CNT/C-OH having a strong affinity to adsorb with the regenerated cellulose and thus to enhance its hydrolytic ability to convert to sugar. In a low-acid aqueous system with CNT/C-OH, the cellulose conversion and the glucose yield reach 94.62 and 78.82%, respectively. A good reusability of CNT/C-OH is also found in multiple steps of hydrolysis of the regenerated cellulose to sugar.