Graphene-like porous carbon nanosheets for ultra-high rate performance supercapacitors and efficient oxygen reduction electrocatalysts

摘要

Here, for the first time, graphene-like porous carbon nanosheets have been constructed by triethanolamine intercalation of layered peanut seed coats followed by simultaneously thermal exfoliation and pyrolysis. The asprepared carbon nanosheets (GPCN-PSC-900) possess graphene-like nanostructure (with thickness of similar to 4 nm), high BET surface area (887 m(2)g(-1)), and abundant nitrogen doping (3.4 at.%), which benefit the improvement of conductivity (8.1 S cm(-1)) and wettability. Due to these merits, the GPCN-PSC-900-based supercapacitor shows ultra-high rate capabilities (76.3% and 72.5% of capacity retention at 1-200 A g(-1) and excellent stabilities (94.7% and 92.3% of capacity retention after 20,000 cycles at 10 A g(-1)) in 6.0 M KOH and 1.0 M Na2SO4 electrolytes, respectively. Furthermore, the GPCN-PSC-900 also exhibits excellent ORR activity (E-0 = 0.970 V; E-1/2 = 0.829 V vs. RHE) and high stability in alkaline media, which make it an efficient air cathode for the Zn-air battery. This work presents a new kind of GPCNs that derive from renewable biomass (peanut seed coats) for energy storage and conversion.