Supporting Information

Rich N/O/S Co-Doped Porous Carbon with High Surface Area from

Silkworm Cocoon for Superior Supercapacitors

Jianyu Huang, Simin Liu, Zifang Peng, Zhuoxian Shao, Yuanyuan Zhang, Hanwu

Dong, Mingtao Zheng, Yong Xiao* and Yingliang Liu*

College of Materials and Energy, South China Agricultural University, Guangzhou

510642, China

Fig. S1 SEM images of SC-PC-900

Electronic Supplementary Material (ESI) for New Journal of Chemistry.This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2019

Fig. S2. The thermal gravimetric analysis curve of SC-PC-900.

Fig. S3 (a) XRD profiles and (b) Raman spectra of the as-synthesized SC-PCs.

Fig. S4 (a) N2 adsorption-desorption isotherms and (b) pore-size distribution (PSD)

curves of control sample.

Fig. S5 XRD patterns of WAW-SC-PC-900.

Fig. S6 CV curves of (a) SC-PC-600, (c) SC-PC-700 and (e) SC-PC-800 at different

scan rates from 5 to 100 mV s-1. GCD curves of (b) SC-PC -600, (d) SC-PC-700 and

(f) SC-PC-800 from 0.5 to 50 A g-1.

Fig. S7 GCD curves of SC-PCs at a current density of 0.5 A g-1.

Fig. S8 Nyquist plots of SC-PCs in three-electrode systems by using 6 M KOH

aqueous solution as electrolyte.

Fig. S9 Electrochemical measurements of the SC-PC-900-based supercapacitors in 6

M KOH electrolyte: (a) CV curves at various scan rate and (b) GCD curves at various

current densities. (c) Specific capacitance of single electrode in supercapacitors at

different current density. (d) Ragone plot of the SC-PC-900-based supercapacitors.

Fig. S10 Specific capacitance of SC-PC-900-based supercapacitor at different current

density using 1 M Na2SO4 as electrolyte.

Table S1 Comparison the heteroatom content and surface area of porous carbon

derived from silkworm cocoon.

Element contentSource SBET

(m2 g-1) Total content N O S

Ref.

Silkworm cocoon 2826 21.9 wt. % 7.3 wt. % 13.0 wt.% 1.6 wt. % This work

Silkworm cocoon 2557 15.8 wt. % 5.1 wt. % 10.7 wt. % - [1]

Silkworm cocoon 796 15.5 at. % 4.5 at. % 11.0 at. % [2]

Silkworm cocoon 3134 10.8 at. % 1.7 at. % 9.1 at. % - [3]

Silkworm cocoon 3841 8.33 at. % 3.24 at. % 5.09 at. % - [4]

Silkworm cocoon 2494 8.2 wt. % 4.1 wt. % 4.1 wt. % [5]

Silkworm cocoon 230 6.7 at. % 6.7 at. % [6]

Silkworm cocoon 2797 6.6 at. % 2.25 at. % 4.05 at. % 0.30 at. % [7]

Silkworm cocoon 2181 5.9 wt. % 5.9 wt. % [8]

Silkworm cocoon 768 5.12 at. % 5.12 at. % - - [2]

Silkworm cocoon 1333 4.16 at. % 4.16 at. % - - [9]

Silkworm cocoon 3514 1.58 at. % 1.58 at. % - [10]

Silkworm cocoon 3243 1.5 wt. % 1.5 wt. % - [8]

Table S2. Contents of C 1s, O 1s, N 1s and S 2p of the as-resulted samples.

Samples XPS (at%) Element analysis (wt%)

C O N S C O N S

SC-PC-600 74.65 14.26 9.25 0.20 66.3 18.6 11.2 0.9

SC-PC-700 75.13 14.20 8.86 0.24 67.1 17.0 11.1 1.3

SC-PC-800 76.65 14.68 7.84 0.31 70.4 14.0 10.5 1.4

SC-PC-900 78.21 13.25 7.08 0.50 74.9 13.0 7.3 1.6

Table S3. Porosity parameters of the as-prepared samples.

SamplesSBET

(a)

[m2 g-1]Smicro

(b)

[m2 g-1]Smeso

(c)

[m2 g-1]Vt

(d)

[cm3 g-1]Vmicro

(e)

[cm3 g-1]DHK

(f)

[nm]DBJH

(g)

[nm]Capacitance

(F g–1)(h)

SC-PC-600 1528 1078 450 0.65 0.42 0.77 2.45 288

SC-PC-700 1866 1454 412 0.78 0.55 0.79 2.37 331

SC-PC-800 2549 2068 481 1.09 0.89 0.82 2.18 393

SC-PC-900 2826 2356 470 1.20 0.93 0.84 2.25 435

Control

sample34 0 34 0.02 0 - 5.39 39

(a) Specific surface area from multiple BET (Brunauer–Emmett–Teller) method.

(b) Micropore surface area from t-plot method.

(c) T-plot method external surface area (Smeso=SBET –Smicro).

(d) Total pore volume at P/P0= 0.99.

(e) The volume of micropores was determined by t-plot method.

(f) DHK represents the median micropore size by the Horvath-Kawazoe (HK) method.

(g) DBJH stands for the Barrett-Joyner-Halenda (BJH) desorption average pore width.

(h) At a current density of 0.5 A g−1.

Table S4 Summary of BET surface areas, activation method and activation agent for

the reported hierarchal porous carbons derived from different precursors.

Refer.Number

SBET (m2 g-1)

Activation Method Activation Agent Biomass

This work 2826 Chemical KOH Silkworm Cocoon

[11] 3251 Chemical KOH Starch

[12] 1510 Chemical KOH Starch

[13] 2316 Chemical KOH Wheat straw

[14] 2157 Chemical KOH Pig bone

[15] 2273 Chemical KOH Fish scale

[16] 1273 Chemical KOH Cherry stones

[17] 416 Chemical KOH Waste news paper

[18] 2405 Chemical KOHEnteromorpha

prolifera

[18] 1204 Chemical KOHEnteromorpha

prolifera

[19] 2106 Chemical KOH Fermented rice

[20] 1413 Chemical KOH Bamboo

[21] 169 Chemical KOH Bamboo

[22] 2073 Chemical KOH Algae

[23] 2855 Chemical KOH Silk

[24] 2496 Chemical ZnCl2+FeCl3 Silk

[25] 2454 Chemical KOH Silk fibroin

[26] 2490 Chemical KOH Bluestem

[26] 1616 Chemical NaOH Bluestem

[26] 552 Chemical NaHCO3 Bluestem

[27] 2111 Chemical KOH Coffee grounds

[28] 1758 Chemical KOH Artemia cyst shell

[29] 491 Chemical H3PO4 Bacterial cellulose

[30] 3270 Chemical KOH Seaweed

[30] 2170 Chemical KOH Seaweed

[31] 3054 Chemical KOH Corncob

[32] 1776 Chemical KOH Willow catkins

[33] 1589 Chemical KOH Willow catkins

[34] 1586 Chemical KOH Willow catkins

[35] 1929 Chemical KOH Olive pits

[36] 1081 Chemical KOH Shiitake mushroom

[36] 2988 Chemical H3PO4+KOH Shiitake mushroom

[36] 1315 Chemical H3PO4 Shiitake mushroom

[37] 3398 Chemical KOH Bean dregs

[37] 2555 Chemical KOH Bean dregs

[38] 2130 Chemical H3PO4 Soybean residue

[39] 580 Chemical KOH Soybean

[40] 1124 Physical Air Grape seed

[41] 3350 Chemical KOH Sisal fiber

[42] 2140 Chemical KOH Cornstalks

[43] 2296 Chemical KOH Bagasse

[44] 1154 Chemical KOH Plane tree

Table S5 Collection of Rs, Rct , Rw, RESR of typical sample according to fitting ESI

data.

Sample Rs Rct Rw RESR

SC-PC-600 0.29 <0.01 129 129.29

SC-PC-700 0.18 <0.01 18.38 18.56

SC-PC-800 0.30 0.26 2.33 2.89

SC-PC-900 0.20 0.17 1.54 1.91

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