Insights into forming behavior and CO2 adsorption properties of graphene from Sargassum horneri by Fe(NO3)3/KOH activation

Abstract

AbstractBACKGROUNDMacroalgae biomass as a graphene source shows great potential at large scale in an energy shortage era. To achieve a more moderate and economic graphene synthesis method, porous graphenes were synthesized using Sargassum horneri as precursor, in combination with Fe(NO3)3 and KOH composite.RESULTSThe addition of 10 wt% Fe(NO3)3 obviously accelerated KOH activation and decreased KOH loading and reaction temperature. Meanwhile, the graphene synthesized by Fe(NO3)3/KOH had better regeneration performance than that activated merely by KOH, even under more moderate thermal condition. The porous graphene displayed high specific surface area (~2311 m2 g−1) and exhibited good CO2 uptake capacity (~4.39 mmol g−1) at 30 °C and 1 bar. The CO2 adsorption rate equations of the graphene were consistent with the intraparticle diffusion model, indicating that CO2 adsorption was mainly controlled by the pore structure and additionally influenced by the chemical functional groups.CONCLUSIONThe present work focuses on the high value‐added comprehensive utilization of macroalgae, which not only has important significance for on‐scale preparation of bio‐originated graphene and CO2 adsorption, but also has positive benefits for macroalgae resource development. © 2022 Society of Chemical Industry (SCI).