Cation exchanged MOF-derived nitrogen-doped porous carbons for CO2 capture and supercapacitor electrode materials

Abstract

A new strategy was developed to introduce active site K⁺ into the pores of MOF precursors, and various N-doped hierarchical porous carbons were prepared in a one-step synthetic route. The effect of K⁺in situ activation on the textural properties of the derived porous carbons was studied systematically, and the CO₂ capture properties and electrochemical performance of these porous carbons were enhanced for their application in supercapacitors. The KBM-700 sample derived from K@bio-MOF-1 (potassium-ion-exchanged bio-MOF-1), which had high nitrogen content (10.16%) and micropore volume (73%), exhibited good CO₂ uptakes (4.75 mmol g⁻¹), and high adsorption selectivity for CO₂/N₂ at 298 K and 1 bar (S_ads = 99.1) as well as high specific capacitance (230 F g⁻¹) and excellent electrochemical cycling stability (97% retention after cycling 10 000 times).