Supporting Information Engineering Two-Dimensional Mass-Transport Channels of MoS 2 Nanocatalyst towards Improved Hydrogen Evolution Performance Ge Wang a, Jingying Tao a, Yijie Zhang a, Shengping Wang a, Xiaojun Yan a, Congcong Liu a, Fei Hu a, Zhiying He a, Zhijun Zuo b, *, Xiaowei Yang a, * a Institute for Regenerative Medicine, Shanghai East Hospital, School of Materials Science and Engineering, Tongji University, Shanghai 200123, China. b Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China Corresponding Author *Email: yangxw@tongji.edu.cn; zuozhijun@tyut.edu.cn. S-1
Figure S1. Characterization of the synthesized MoS 2 powders. (a) TEM image; (b) XRD pattern; (c, d) XPS scans for the Mo and S binding energies. S-2
Figure S2. The mechanism of the structural formation of channel-engineered MoS 2. Figure S3. SEM image of the cross-section of channel-engineered MoS 2. S-3
Figure S4. TEM image of carbon black. Figure S5. The HER performance of Pt/C, MS/C and MS. S-4
Figure S6. Cyclic voltammetry curves of MS (a) and MS/C (b) in the region of 0.25-0.35 V vs SCE. Figure S7. Cyclic voltammetry curves of carbon black (a) and its plot of the extraction of C dl (b). S-5
Figure S8. Corresponding Randles equivalent circuit model of these MoS 2 electrode. Figure S9. The comparison of electrocatalytic properties between MS/Si, MS/C and MS. S-6
Figure S10. Durability test for the MS/C via cyclic voltammetry and chronopotentiometry curves (inset) at constant current densities of 100 ma cm -2. Figure S11. Comparison of overpotential and Tafel slope at the 2D substrate with other recently reported promising MoS 2 nanocatalysts. S-7
Figure S12. Comparison of overpotential and Tafel slope at 3D substrate with other recently reported promising MoS 2 nanocatalysts. Table S1. The R s, R i and R ct of MS and MS/C. R s (Ω) R i (Ω) R ct (Ω) MS 6.98 20.0 60.5 MS/C 6.43 1.42 4.34 S-8
Table S2. Comparison of the HER performance with other recently reported promising MoS 2 nanocatalysts at 2D electrode. Loading (mg cm -2 ) j (ma cm -2 ) (η = 227mV) Tafel slope (mv decade -1 ) Year MS/C 0.211 100 39.4 This work MoS 2 nanoparticles/graphene 1 0.281 ~45 ~41 2011 Amorphous MoS 2 2 0.196 ~25 60 2012 Conducting MoS 2 nanosheets 3 0.050 ~15 ~40 2013 Disorder engineered and oxygen-incorporated MoS 2 4 0.281 40 55 2013 Edge-terminated MoS 2 5 0.28 120 49 2015 Metallic phase MoS 2 nanosheets 6 0.043 ~50 41 2016 Edge-oriented and Interlayer expanded MoS 2 /rgo 7 0.255 ~25 43.5 2017 Nitrogen doped MoS 2 nanosheets 8 0.285 ~30 40.5 2017 Size-controlled MoS 2 nanodots supported on 0.453 ~10 59.8 2017 reduced graphene oxide 9 Amorphous MoS 2 /CNTs 10 61 36 2017 S-9
Table S3. Comparison of the HER performance with other recently reported promising MoS 2 nanocatalysts at 3D electrode. Loading (mg cm -2 ) j (ma cm -2 ) (η = 191mV) Tafel slope (mv decade -1 ) Year MS/C-CP 1 100 36 This work Li-tuning vertical aligned MoS 2 /CFP 11 36 44 2013 MoS 2 /N-doped CNT forest 12-67 40 2014 Amorphous MoS x Cl y /vertical graphene growth at graphit 45 46 2015 disk 13 Basal planes activated and S- terminated MoS 2 /CC 14 5 49 2017 Stepped edge engineered MoS 2 /CFP 15 125 59 2017 MoS 2 grown on graphene/cfp 1 1 30 41 2011 MoS x /Ni foam 16 40 42.8 2013 MoS 2 nanoparticles/carbon nanofiber foam 17 5 44 2015 MoS 2 /CPs 18 80 41 2015 MoS 2 /vertical graphene on CC 19 38 53 2015 S-10
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