Biomass-derived grapene-like porous carbon nanoflakes for advanced supercapacitor and hydrogen evolution reaction

It is valuable that graphene-like porous carbon materials are prepared from the biomass resources due to theirs porous structure, heteroatom, and high specific surface area. Herein, we use egg white and graphene oxides as precursor and employ post-hydrothermal carbonization approach, freeze-drying technique, carbonization, and activation methods by KOH to prepare the graphite carbon nanoflakes with Fe7C3@graphite carbon nanoflakes hybrid materials. Morphology tests imply that the formation of graphite carbon nanoflakes are mainly depended by activation step, it implies that carbon flakes are exfoliated via introducing K+ into carbon layers and further destroying the van der Waals force (VDWF). As a result, this hybrid materials exhibit a attractive capacitance (528 mF·cm-2@1 mA·cm-2) and durability (91@10 mA·cm-2, 4000 cycles). For hydrogen evolution reaction (HER), the as-collected samples also deliver a low overpotential and remarkable stability. We believes that the as-obtained hybrid materials have a greatly application value in energy storage devices.