Supporting Information

Facile Synthesis of Nitrogen-Doped Carbon Nanosheets as Metal-Free catalyst with Excellent Oxygen Reduction Performance in Alkaline and Acidic Media

Qiuping Zhao1 , Qin Ma1, Fuping Pan2, Zhengmin Wang1 , Baoping Yang1 , Jianqiang Zhang1, Junyan Zhang2﹡

1 School of Petroleum Chemical Engineering, Lanzhou University of Technology, Lanzhou 730050, P.R. China

2 State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P.R. China

*Corresponding Author:

E-mail: ;

Tel & Fax: +86-0931-4968295.

Professor of Chemistry

Professor of Material Science and Engineering

Fig. S1 TGA characterization of corn starch

Fig. S2 Nitrogen adsorption/desorption isotherm plot of (a) NCN-800, (b) NCN-900 (c) NCN-1000 and (d) Pt/C, with an inset showing the DFT pore distribution.

Tab. S1 Textural properties of the NCN

Sample / BET surface area
(m2/g) / Pore volume
(cm3/g)（BJH D） / Average pore size
(nm)(BJH A)
NCN-800 / 341.20 / 1.43 / 17.90
NCN-900 / 435.69 / 1.94 / 21.41
NCN-1000 / 1568.85 / 3.65 / 12.43

Fig. S3 High-resolution C1s XPS spectra of (a) NCN-800, (b) NCN-900, and (c) NCN-1000.

Fig. S4 (a) LSV curves with various rotation rates of Pt/C electrode, (b) Koutecky–Levich plots of Pt/C electrode in O2-saturated 0.1M KOH electrolyte with a sweep rate of 5 mV s−1.

Fig. S5 (a) LSV curves with various rotation rates of Pt/C electrode, (b) Koutecky–Levich plots of Pt/C electrode in O2-saturated 0.5 M H2SO4 electrolyte with a sweep rate of 5 mV s−1.

Tab. S2 The JK of NCN-1000 and Pt/C per unit mass and surface area at -0.20V

in 0.1 M KOH solution

Sample / Jk/ mA cm-2 / Mass activity
/ mA cm-2 mg-1 / Specific activity
/ mA cm-2 Area-1
NCN-1000 / 8.10 / 405.00 / 5.16 *10-3
Pt/C / 6.21 / 310.50 / 3.74 *10-2

Tab. S3 The JK of NCN-900 and Pt/C per unit mass and surface area at 0.40 V

in 0.5 M H2SO4 solution

Sample / Jk/ mA cm-2 / Mass activity
/ mA cm-2 mg-1 / Specific activity
/ mA cm-2 Area-1
NCN-900 / 4.80 / 240.00 / 1.10*10-2
Pt/C / 8.74 / 437.00 / 5.26*10-2

Tab. S4 Surface composition concentration of GNCN

Sample / Carbon
(at.%) / Oxygen
(at.%) / Nitrogen total
(at.%)
GNCN-900 / 90.85 / 4.11 / 5.04
GNCN-1000 / 93.82 / 2.34 / 3.84

Fig. S6 XPS survey spectra of GNCN.

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