摘要
Nitrogen-doped carbon materials with a large specific surface area,high conductivity,and adjustable microstructures have many prospects for energy-related applications.This is especially true for N-doped nanocarbons used in the electrocatalytic oxygen reduction reaction(ORR)and supercapacitors.Here,we report a low-cost,environmentally friendly,large-scale mechanochemical method of preparing N-doped porous carbons(NPCs)with hierarchical micro-mesopores and a large surface area via ball-milling polymerization followed by pyrolysis.The optimized NPC prepared at 1000°C(NPC-1000)offers excellent ORR activity with an onset potential(Eonset)and half-wave potential(E1/2)of 0.9 and 0.82 V,respectively(vs.a reversible hydrogen electrode),which are only approximately 30 mV lower than that of Pt/C.The rechargeable Zn–air battery assembled using NPC-1000 and the NiFe-layered double hydroxide as bifunctional ORR and oxygen evolution reaction electrodes offered superior cycling stability and comparable discharge performance to RuO2 and Pt/C.Moreover,the supercapacitor electrode equipped with NPC prepared at 800℃ exhibited a high specific capacity(431 F g^−1 at 10 mV s^−1),outstanding rate,performance,and excellent cycling stability in an aqueous 6-M KOH solution.This work demonstrates the potential of the mechanochemical preparation method of porous carbons,which are important for energy conversion and storage.
Nitrogen-doped carbon materials with a large specific surface area, high conductivity, and adjustable microstructures have many prospects for energy-related applications. This is especially true for N-doped nanocarbons used in the electrocatalytic oxygen reduction reaction(ORR) and supercapacitors. Here, we report a low-cost, environmentally friendly, large-scale mechanochemical method of preparing N-doped porous carbons(NPCs) with hierarchical micro-mesopores and a large surface area via ball-milling polymerization followed by pyrolysis. The optimized NPC prepared at 1000 °C(NPC-1000) o ers excellent ORR activity with an onset potential(Eonset) and half-wave potential(E1/2) of 0.9 and 0.82 V, respectively(vs. a reversible hydrogen electrode), which are only approximately 30 m V lower than that of Pt/C. The rechargeable Zn–airbattery assembled using NPC-1000 and the Ni Fe-layered double hydroxide as bifunctional ORR and oxygen evolution reaction electrodes o ered superior cycling stability and comparable discharge performance to RuO2 and Pt/C. Moreover, the supercapacitor electrode equipped with NPC prepared at 800 °C exhibited a high specific capacity(431 Fg-1 at 10 m V s-1), outstanding rate, performance, and excellent cycling stability in an aqueous 6-M KOH solution. This work demonstrates the potential of the mechanochemical preparation method of porous carbons, which are important for energy conversion and storage.
基金
financial support from NSFC(51602332)
the National Key Research and Development Program of China(2016YFB0700204)
Science and Technology Commission of Shanghai Municipality(15520720400,16DZ2260603)
Equipment Research Program(6140721050215)
the National 1000 Youth Talents program of China
financial support from Ningbo 3315 program
DST Solar Energy Harnessing Centre(DST/TMD/SERI/HUB/1(C)),DST Materials for Energy Storage program,Ministry of Electronics and Information Technology(India)(Project ID:ELE1819353MEITNAK)