Fabrication of microfibrillated cellulose from biomass by use of carbon nitride with high nitrogen/carbon ratio

Microfibrillated cellulose (MFC) as an attractive green bio-based material has attracted widespread attention in recent years due to its non-toxicity, degradability, excellent performance, and high aspect ratio. In this study, the g-C₃N₅ with a high nitrogen/carbon ratio was prepared as a catalyst through the self-polymerization of a nitrogen-rich precursor. The triazole groups at the edges of g-C₃N₅ were proven to exhibit strong adsorption to biomass and strong alkalinity. In a low-acidic aqueous system with g-C₃N₅, MFC with diameters of 100-200 nm and lengths up to 100 μm was fabricated from various biomasses within 5 min under microwave radiation. The ultimate yield of the MFC produced from viscose reached 90 %. Young's modulus of the MFC reaches 3.7 GPa. This work provides a particular method with high efficiency to prepare MFC with excellent properties from biomass by chemical method.