Supplementary Figure S1 TEM images. TEM images of mesoporous polymer nanospheres (MPNs-n) synthesized with different ethanol amount. S1
Supplementary Figure S2 Photography. Photography illustration of the solution color change during the synthesis of diverse mesoporous polymer nanospheres (MPNs-n) with different ethanol amount. S2
Supplementary Figure S3 TEM image. TEM image of the mesoporous aminophenol and formaldehyde resins polymer nanospheres (MPNs-32) synthesized by using aminophenol and formaldehyde as precusors. S3
Weight loss (wt%) Weight rentention (Wt%) 100 90 80 70 d) c) b) 60 50 a) 40 0 100 200 300 400 500 600 700 800 Temperature ( C) Temperature ( o C) Supplementary Figure S4 Thermogravimetric analyses of mesoporous polymer nanospheres (MPNs-1) after the pyrolysis at different temperature. (a) 350 C; (b) 400 C; (c) 500 C; (d) 520 C. S4
Supplementary Figure S5 Morphological and structural characterization of the mesoporous carbon nanospheres (MCNs). SEM (a-d), HRSEM (e-h), and TEM images (i-l) of the MCNs-12 (a), (e), (i) derived from MPNs-12 synthesized with 20 ml ethanol; the MCNs-1 (b), (f), (j) derived from MPNs-1 synthesized with 26 ml ethanol; the MCNs-2 (c), (g), (k) derived from MPNs-2 synthesized with 29 ml ethanol; and the MCNs-19 (d), (h), (l) derived from MPNs-19 synthesized with 30 ml ethanol. S5
Supplementary Figure S6 Morphological and structural characterization of the mesoporous carbon nanospheres and sulfur composites. (a) Thermogravimetric analysis, (b) Energy-dispersive X-ray spectroscopy (EDS), (c), (d) TEM images of the carbon spheres MCN-1@S composites. S6
Current Density (ma/cm 2 ) Current Density (ma/cm 2 ) a b 0.0 0.0-0.5-0.2-1.0-1.5-0.4-0.6 O 2 N 2-2.0-2.5 graphitie powder MCNs-1 N-graphene (ref) -1.2-0.8-0.4 0.0 Potential (V vs Hg/HgO) -1.0-0.8-0.6-0.4-0.2 0.0 Potential (V vs Hg/HgO) Supplementary Figure S7 Catalytic activity towards electrochemical reduction of oxygen in 0.1 M KOH aqueous solution at room temperature. (a) Cyclic voltammetry of the MCNs-1 performed in O 2 and N 2 ; (b) Linear sweep voltammograms (LSV) of various catalysts on a rotating disk electrode (RDE, 1200 rpm) in O 2 -saturated 0.1 M KOH, the result of N-graphene is from reference 26. Supplementary Fig. S7a compares the CV behaviour of mesoporous carbon spheres as a response of oxygen reduction. In contrast to the feature-less CV curve in nitrogen saturate electrolyte, greatly enhanced current density and well resolved redox peaks are recognizable in oxygen saturated electrolyte. It is evident that MCNs-1 exhibits ability to reduce oxygen. The first reduction peak at -0.4 V vs Hg/HgO refers to the two-electron transfer reaction from O 2 to HO 2 -. At more negative potential (around - 0.8V vs Hg/HgO), the superoxide anion can be further reduced to OH -. The overall reaction is a two-step four-electron transfer reaction. On the ORR polarization curves (Fig. S7b), MCNs-1 shows a much better ORR activity than that of natural graphite powder without any nanostructure. It is generally accepted that nitrogen doping can largely enhance the ORR performance of carbon-based catalyst. However, containing carbon only, the MCNs-1 shows comparable ORR activity with that of nitrogen doped graphene 1, which might be due to its excellent oxygen reactant mass transfer and nanoconfined effect. Therefore, enhanced ORR activity would be predicted by engineering MCNs-1 through hetero-atom incorporation. S7
Supplementary Figure S8 TEM images and hydrogen evolution reaction performance of the Pt deposited mesoporous carbon nanospheres (Pt-MCNs-1). TEM images (a, b) of the Pt-loaded MCN-1; Linear scanning voltammetry (c) of the Pt-loaded MCNs-1 in 0.5 M H 2 SO 4 saturated with N 2, and (d) Tafel plot of the HER and the Tafel slope of the Pt-loaded MCN-1. S8
Supplementary Figure S9 TEM images. TEM images of mesoporous polymer nanospheres (MPNs-n) synthesized with ethanol amount of 26 ml (a-c) and 29 ml (d-f) but different FC4 amount. S9
Supplementary Figure S10 TEM images. TEM images of mesoporous polymer nanospheres (MPNs-n) synthesized with ethanol amount of 26 ml (a-c) and 29 ml (d-f) but different TMB amount. S10
Supplementary Figure S11 TEM images. TEM images of mesoporous polymer nanospheres (MPNs-n) synthesized in the absence of ethanol with different TMB amount: (a) MPNs-33, TMB 0.0 g; (b) MPNs-34, TMB 0.5 g; (c) MPNs-35, TMB 2.0 g; (d) MPNs-36, TMB 4.0 g. S11
Supplementary Figure S12 TEM images. TEM images of mesoporous polymer nanospheres (MPNs-n) synthesized at ethanol amount of 26 ml and different initial synthesis temperature: (a) MPNs-29, 20 C; (b) MPNs-1, 30 C; (c) MPNs-30, 40 C; and (d) MPNs-31, 50 C. S12
Supplementary Table S1 Properties and synthesis parameters of mesoporous polymer nanospheres (MPNs-n). Sample FC4 amount (g) Pluronic F127 amount (g) TMB amount (g) Initial synthesis temperature ( C) Ethanol (ml) Average particle size (nm) MPNs-1 0.2 1.0 1.0 30 26 400 MPNs-2 0.2 1.0 1.0 30 29 350 MPNs-3 0.2 1.0 1.0 30 0 80 MPNs-4 0.2 1.0 1.0 30 2 100 MPNs-5 0.2 1.0 1.0 30 5 110 MPNs-6 0.2 1.0 1.0 30 9 120 MPNs-7 0.2 1.0 1.0 30 15 150 MPNs-8 0.2 1.0 1.0 30 16 110 & 300 MPNs-9 0.2 1.0 1.0 30 17 110 & 350 MPNs-10 0.2 1.0 1.0 30 18 110 & 380 MPNs-11 Effect 0.2 1.0 1.0 30 19 170 &400 MPNs-12 of 0.2 1.0 1.0 30 20 400 MPNs-13 Ethanol 0.2 1.0 1.0 30 21 400 MPNs-14 0.2 1.0 1.0 30 22 400 MPNs-15 0.2 1.0 1.0 30 24 400 MPNs-16 0.2 1.0 1.0 30 25 400 MPNs-17 0.2 1.0 1.0 30 27 350 MPNs-18 0.2 1.0 1.0 30 28 350 MPNs-19 0.2 1.0 1.0 30 30 350 MPNs-20 0.2 1.0 1.0 30 40 380 MPNs-21 0.0 1.0 1.0 30 26 350 MPNs-22 Effect 0.4 1.0 1.0 30 26 450 MPNs-23 of 0.0 1.0 1.0 30 29 350 MPNs-24 FC4 0.4 1.0 1.0 30 29 450 MPNs-25 0.2 1.0 0.0 30 26 2000 MPNs-26 Effect 0.2 1.0 2.0 30 26 300 MPNs-27 of 0.2 1.0 0.0 30 29 2000 MPNs-28 TMB 0.2 1.0 2.0 30 29 300 MPNs-29 Effect 0.2 1.0 1.0 20 26 40 MPNs-30 of 0.2 1.0 1.0 40 26 200 MPNs-31 IST 0.2 1.0 1.0 50 26 100 MPNs-32 a APF 0.2 1.0 1.0 30 26 400 MPNs-33 0.2 1.0 0.0 30 0 80 MPNs-34 Effect 0.2 1.0 0.5 30 0 80 MPNs-35 of 0.2 1.0 2.0 30 0 80 MPNs-36 TMB 0.2 1.0 4.0 30 0 80 a aminophenol and formaldehyde as precursors S13
Supplementary Table S2 Physicochemical Properties of Mesoporous Carbon Nanospheres (MCNs-n) obtained by the carbonization of MPNs-n at 400 C for 6 hr, then at 800 C for 6 hr. Sample BET surface area (m 2 g -1 ) Pore size (nm) Particle size (nm) Total pore volume (cm 3 g -1 ) MCNs-1 MCNs-2 857 640 3.5 3.5 350 300 0.45 0.34 S14
Supplementary Reference 26. Zheng Y., Jiao Y., Ge L., Jaroniec M. & Qiao S.Z., Two-Step Boron and Nitrogen Doping in Graphene for an Enhanced Synergistic Catalysis. Angew. Chem. Int. Ed. 52, 3110 3116 (2013). S15