Preparation And Electrochemical Performance Of Carbon Materials Derived From Pyridine-based Porous Organic Frameworks

The overexploitation of fossil fuels had led to severe environment problem and environmental pollution problem.As the new energy conversion and storage devices,fuel cells and supercapacitors had received widespread attention due to their high efficiency and low pollution.Because of its rich pore structure,high specific surface area,easy functionalization,and other properties,porous organic frames materials played an important role in the areas of energy storage and conversion.In this paper,a series of porous organic frameworks materials?POFMs?had been synthesized by using pyridine-based compounds as the main monomers,and a series of heteroatom-doped carbon materials had been prepared by the high-temperature pyrolysis of the POFMs.Moreover,this paper presented the investigation and analysis for the catalytic mechanism and electrochemical charge storage mechanism based on the parameters of chemical composition,morphology,microstructure,electrochemical performances.The main contents include the following two parts:?1?Preparation and electrochemical performance of nitrogen-doped carbon materials derived from pyridine-based porous organic polymers.In this work,a novel nitrogen-doped porous carbon nanomaterial had been synthesized by directly pyrolyzing the tetrazine/pyridine/triazine-containing porous organic polymer under inert conditions.Benefiting from the high surface area(574 m² g^–1)and enriched nitrogen doping?5.63 at.?%N?,the obtained porous carbon nanoparticles?TPOP-900?used as metal-free ORR electrocatalyst possessed better electrochemical performance(E₀=11 m V;E_1/2=-90 m V vs Ag/Ag Cl)than that of Pt/C.Moreover,served as electrode material for supercapacitor,the TPOP-900 exhibited relatively high specific capacitance(250 F g^–1 at 0.5 A g^–1)and excellent cycling stability?95.75%capacitance retention after 10?000 cycles?in 6 M KOH aqueous electrolyte.?2?Preparation and electrochemical performance of sulfur and nitrogen dual-doped carbon materials derived from pyridine-based hydrogen-bonded organic frameworks.Here,a novel graphene-like porous carbon nanosheets?GPCNs?had been synthesized by a simple and cost-effective bottom-up method,which including molecule self-assembly into layered precursors,simultaneous nonorganic molecules intercalation,and subsequent thermal-induced exfoliation and activation.The as-prepared sulfur and nitrogen dual-doped GPCNs?HOF-700-3?had graphene-like nanostructures,relative large specific surface area(383 m² g^–1).As the supercapacitor electrode,HOF-700-3 presented relatively high specific capacitance of 252 F g^–1 at 0.5 A g^–1and capacitance retention of 54%at 20 A g^-1,as well as excellent stability of 97.6%capacity retention after 10 000 cycles at 5 A g^-1 in 6 M KOH electrolyte.