From cellulose to graphene-like porous carbon nanosheets

Graphene has attracted attention in various scientific and theoretical areas. The molten-salt/activation method has emerged as an effective method for graphene-like porous carbon nanosheets (GPCNs) synthesis. This method involves simultaneous pyrolysis and activation of carbon precursors in molten salt to generate GPCNs. In the FeCl3/ZnCl2 system, the iron component facilitates the generation of GPCNs by forming a complanate carburized phase in the pyrolysis process, and ZnCl2 activate the formed carbon to produce a porous structure. This work's scientific contribution was to synthesize GPCNs with a high specific surface area from cellulose. A change in cellulose fibers' morphology has been verified, with the consequent formation of nanosheets caused by the chemical treatment employed. The GPCNs produced had a considerable specific surface area (up to 1228 m2 g-1). The increase of the ZnCl2 ratio caused an increase in the samples' total pore volume (from 0.6 to 1.0 cm3 g-1: temperature of 700 degrees C, from 0.54 to 1.01 cm3 g-1: 800 degrees C and from 0.16 to 0.53 cm3 g-1: 900 degrees C). The materials produced are made up of micropores and narrow mesoporous (between 10 and 90 A). The yields of GPCNs varied between 3.9 and 33.4 wt%. The 800G6 sample showed the highest degree of graphitization. The specific surface area for this condition was 1208 m2 g-1 and the yield (wt%) was 7.3. From the results presented in this work, it can be highlighted that it was possible to obtain materials with high added value from a simultaneous activation-graphitization method of cellulose.

Automated summary

Graphene-like porous carbon nanosheets (GPCNs) were synthesized effectively using the molten-salt/activation method. The FeCl3/ZnCl2 system demonstrated the formation of GPCNs with high specific surface area, influenced by the iron component facilitating carburization and the activation by ZnCl2. The materials produced exhibited a significant total pore volume and were composed of micropores and narrow mesoporous structures, with varying yields and degrees of graphitization.