Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2018 Supporting Information In-situ Growth of Single-Layered α-ni(oh) 2 Nanosheets on Carbon Cloth for High-Efficient Electrocatalytic Urea Oxidation Chong Lin 1,2, Zhengfei Gao 1,2, Feng Zhang 1, Jianhui Yang 2, Bin Liu 2, Jian Jin 1* 1 i-lab, CAS Key Laboratory of Nano-Bio Interface, and CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, P. R. China. 2 Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi an, 710069, P. R. China. Supplementary Figures: Figure S1. Wetting properties of water on SL Ni(OH) 2 NS/CC. A water droplet (4 μl) touches the SL Ni(OH) 2 NS modified CC, and it spreads out quickly within 31.2 ms.
Figure S2. SEM images of (a) and (b) ML Ni(OH) 2 NS and (c) and (d) SL Ni(OH) 2 NS, respectively. Figure S3. Calculated structures of α-ni(oh) 2 (a) and β-ni(oh) 2 (b). The corresponding interlayer distances are labeled. H atoms are intentionally removed.
Figure S4. XRD plots of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solutions with volume ratios (v/v) of 2/1, 1/1 and 1/2, respectively. Figure S5. (a-c) SEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 2/1. (d-f) SEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/1. (g-i) SEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratios (v/v) of 1/2.
Figure S6. (a and b) TEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 2/1. (c and d) TEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/1. (e and f) TEM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/2. Figure S7. (a and b) AFM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 2/1. (c) corresponding height profile.
Figure S8. (a and b) AFM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/1. (c) corresponding height profile. Figure S9. (a and b) AFM images of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/2. (c) corresponding height profile. Figure S10. BET of Ni(OH) 2 NS prepared from CH 3 OH and H 2 O mixed solution with volume ratios (v/v) of 2/1, 1/1 and 1/2, respectively.
Figure S11. (a and b) SEM images of Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 2/1. (c and d) SEM images of Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/1. (e and f) SEM images of Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratio (v/v) of 1/2.
Figure S12. TEM images of Ni(OH) 2 NS prepared from ethanol (a) and propanol (b). (c) corresponding XRD plots. Figure S13. Schematic diagram of the growth mechanism of Ni(OH) 2. Figure S14. CV plots of (a) CC, (b) ML Ni(OH) 2 /CC, and (c) SL Ni(OH) 2 NS/CC under 1M KOH and 0.33 M urea at different scan rates.
Figure S15. LSV plots of ML Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratios (v/v) of 2/1, 1/1 and 1/2 in 1 M KOH & 0.33 M urea, respectively. Figure S16. CV plots of ML Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratios (v/v) of (a) 2/1, (b) 1/1 and (c) 1/2 in 1 M KOH & 0.33 M urea at different scan rates, respectively. (d) corresponding calculated differential current vs scan rates at 0.05 V vs. Ag/AgCl, respectively.
Figure S17. EIS plots of ML Ni(OH) 2 NS/CC prepared from CH 3 OH and H 2 O mixed solution with volume ratios (v/v) of 2/1, 1/1 and 1/2 in 1 M KOH & 0.33 M urea, respectively. Figure S18. SEM images of ML Ni(OH) 2 /CC prepared from water after CA tests for 20,000 s.
Figure S19. (a) CV plots of ML Ni(OH) 2 NS/CC after CA tests for 36,000 s at different scan rates. (b) calculated differential current vs. scan rates at 0.05 V vs. Ag/AgCl. Figure S20. SEM images of CNT paper (a), Ni(OH) 2 NS/CNT paper (b and c), RGO (d), and Ni(OH) 2 NS/RGO (e and f), respectively.
Figure S21. TEM images of (a) and (b) reduced graphene oxide (RGO), (c) and (d) Ni(OH) 2 NS/RGO. Table S1. A summary of the performance of Ni-based catalysts for urea electrooxidation. Ni-based catalysts Electrolytes Potential/current ( V vs ma/cm 2 ) CA (ma/cm 2 vs s) References Rh-Ni foil 1 M KOH& 0.33 M urea 1.524/60 30/1 800 s at 1.4 V S1 Ni(OH) 2 tube/ni foam 1 M KOH& 0.33 M urea 1.708/215 120/300 s at 1568 V S2 Ni/RGO 1 M KOH& 0.33 M urea 1.5/10 9/3 600 s at 1.5 V S3 NiO NS/Ni foam 1 M KOH& 0.33 M urea 1.588/56 54/3 600 s at 1.568 V S4 Ni-WC/C 1 M KOH& 0.33 M urea 1.424/42 8.5/3 600 s at 1.424 V S5 Ni-WC/MWNT 1 M KOH& 0.33 M urea 1.424/48 S6 Ni 1.5Mn 1.5O 4 1 M KOH& 0.33 M urea 1.37/6.9 18/1 000 s at 1.536 V S7 Metallic Ni(OH) 2 1 M KOH& 0.33 M urea 1.496/35 17.5/20 000 s at 1.496 V S8 Ni-P 1 M KOH& 0.33 M urea 1.52/70 41/1 000 s at 1.52 V S9 CE-NiFe/NF 1 M KOH& 0.33 M urea 1.568/70 40/1 000 s at 1.52V S10 SL Ni(OH) 2 NS/CC 1 M KOH& 0.33 M urea 1.512/436.4 171/36 000 s at 1.568 V This work References S1. Rebecca L. King, Gerardine G. Bott. Investigation of multi-metal catalysts for stable hydrogen production via urea electrolysis. J. Power Sources 2011, 196, 9579 9584.
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