title: In-Situ-Activated N-Doped Mesoporous Carbon from a Protic Salt and Its Performance in Supercapacitors.
abstract: Protic salts have been recently recognized to be an excellent carbon source to obtain highly ordered N-doped carbon without the need of tedious and time-consuming preparation steps that are usually involved in traditional polymer-based precursors. Herein, we report a direct co-pyrolysis of an easily synthesized protic salt (benzimidazolium triflate) with calcium and sodium citrate at 850 °C to obtain N-doped mesoporous carbons from a single calcination procedure. It was found that sodium citrate plays a role in the final carbon porosity and acts as an in situ activator. This results in a large surface area as high as 1738 m2/g with a homogeneous pore size distribution and a moderate nitrogen doping level of 3.1%. X-ray photoelectron spectroscopy (XPS) measurements revealed that graphitic and pyridinic groups are the main nitrogen species present in the material, and their content depends on the amount of sodium citrate used during pyrolysis. Transmission electron microscopy (TEM) investigation showed that sodium citrate assists the formation of graphitic domains and many carbon nanosheets were observed. When applied as supercapacitor electrodes, a specific capacitance of 111 F/g in organic electrolyte was obtained and an excellent capacitance retention of 85.9% was observed at a current density of 10 A/g. At an operating voltage of 3.0 V, the device provided a maximum energy density of 35 W h/kg and a maximum power density of 12 kW/kg.
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Tiago C
authors.initials: TC
authors.lastname: Mendes
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Changlong
authors.initials: C
authors.lastname: Xiao
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Fengling
authors.initials: F
authors.lastname: Zhou
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Haitao
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Knowles
authors.affiliation: ARC Centre of Excellence for Electromaterials Science (ACES), Institute for Frontier Materials (IFM), Deakin University , Burwood, Victoria 3125, Australia.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hilder
authors.affiliation: ARC Centre of Excellence for Electromaterials Science (ACES), Institute for Frontier Materials (IFM), Deakin University , Burwood, Victoria 3125, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Somers
authors.affiliation: ARC Centre of Excellence for Electromaterials Science (ACES), Institute for Frontier Materials (IFM), Deakin University , Burwood, Victoria 3125, Australia.
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Howlett
authors.affiliation: School of Chemistry, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: MacFarlane
keywords: N-doped carbon; citrate salts; mesoporous carbon; one-step calcination; protic salts; symmetric supercapacitors