Simple fabrication of Co 3 O 4 nanoparticles on N-doped laser-induced graphene for high-performance supercapacitors.

This study demonstrates a simple strategy to fabricate Co 3 O 4 on N-doped laser-induced graphene (Co 3 O 4 -NLIG) based on duplicate laser pyrolysis, enabling the in situ generation of Co 3 O 4 nanoparticles and heteroatom doping in laser-induced graphene (LIG). Morphological analyses reveal the uniform distribution of Co 3 O 4 nanoparticles on the surface of the LIG structure. The modification of NLIG with Co 3 O 4 nanoparticles results in impressive electrochemical performance due to the contributions from electric double-layer capacitance and pseudocapacitance. The optimal Co 3 O 4 -NLIG is produced at 20 wt% cobalt precursor loading (Co 3 O 4 -NLIG-20). In a three-electrode setup, this electrode exhibits a specific areal capacitance ( C A ) of 216.3 mF cm -2 at a current density of 0.5 mA cm -2 in a 1 M KOH electrolyte. When the optimal electrodes are assembled into a solid-state supercapacitor (Co 3 O 4 -NLIG-SC) using a poly(vinyl alcohol) phosphoric acid (PVA-H 3 PO 4 ) gel electrolyte, a C A of 17.96 mF cm -2 is obtained with good cycling stability.