Supporting Information Synthesis of Ni/Graphene Nanocomposite for ...
Supporting Information
Synthesis of Ni/Graphene Nanocomposite for Hydrogen Storage
Chunyu Zhou,*,† Jerzy A. Szpunar,† and Xiaoyu Cui‡ †
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9,
Canada. ‡
Canadian Light Source Inc., Saskatoon, SK, S7N 2V3, Canada.
Corresponding Author Chunyu Zhou Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon SK S7N 5A9, Canada. *Email: [email protected]
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Figure S1. Digital images of the prepared graphene oxide with increasing concentration from left to right.
Figure S2. (a-e) SEM and (f) TEM morphology observations of graphene sheets.
The homemade apparatus (Fig S2) is mainly equipped with a hydrogen cylinder (HY 5.0UH-T, UHP Grade 99.999%, Praxair), a pressure regulator (KPP1RSH422P2A030, Swagelok), a S-2
sample vessel (250 ml, 453HC-316-0719842151, Parr Instrument), a rupture disc (Parr Instrument), a heater (854HC, Parr Instrument), a pressure gauge (PPC5352, Winters Instrument), a temperature controller (50 °C to 1200 °C, 210/TIMER-K mode, J-KEM Scientific) with a ceramic insulated thermocouple (870 °C, XC-20-K-24, Omega) and a filter (pore size of 0.5 μm, SS-4FW-VCR-2). All tubes (SS-T2-S-028-20), valves (SS-4UG-V51-VS), connectors and fittings (gasket, 457HC2) are purchased from Swagelok. Due to the high operating pressure and potential corrosion, all reactors, valves, connectors and fittings are made of 316 stainless steel. All valves are bellows-sealed with maximum working temperature and pressure of 343 °C and 240 bar, respectively.
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Figure S3. Home-made instrument for hydrogen charging process.
Figure S4. SEM morphology observation of the bare metallic Ni that prepared from hydrogen thermal treatment.
Figure S5. SEM observations of Ni/graphene composites before and after hydrogen charge: (a) Ni/graphene_0 bar and (b) Ni/graphene_60 bar.
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Supporting Discussion The Scherrer analysis of the XRD broadened peaks allows the crystallite size determination of nanocrystals in solid powder with the domain size smaller than 100 nm.1–4 In the spectrum of the Ni/graphene, the crystallite size of Ni nanoparticles was measured by evaluating the Scherrer relation 𝜏 = Kλ/βcosθ to be 7 ~ 9 nm. Where: τ is the mean size of the crystallites, which may be smaller or equal to the grain size; K is a crystallite shape factor, with a value close to unity and the typical value of about 0.9; λ is the X-ray radiation wavelength of radiation [λ(Cr)=0.229 nm]; β is the line broadening of full width at half maximum (FWHM) of Ni(111) or Ni (200) in radians units; θ is the Bragg angle and the peak position in degrees.
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REFERENCE (1)
Alexander, L.; Klug, H. P. Determination of Crystallite Size with the X-Ray Spectrometer. J. Appl. Phys. 1950, 21, 137–142.
(2)
Rogério dos Santos Alves; Alex Soares de Souza, et all. The Scherrer Formula for X-Ray Particle Size Determination. Igarss 2014 2014, 56, 1–5.
(3)
Caņado, L. G.; Takai, K.; Enoki, T.; Endo, M.; Kim, Y. A.; Mizusaki, H.; Jorio, A.; Coelho, L. N.; Magalhães-Paniago, R.; Pimenta, M. A. General Equation for the Determination of the Crystallite Size La of Nanographite by Raman Spectroscopy. Appl. Phys. Lett. 2006, 88, 1–4.
(4)
Perera, S. D.; Mariano, R. G.; Vu, K.; Nour, N.; Seitz, O.; Chabal, Y.; Balkus, K. J. Hydrothermal Synthesis of Graphene-TiO 2 Nanotube Composites with Enhanced Photocatalytic Activity. 2012.
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Synthesis of Ni/Graphene Nanocomposite for Hydrogen Storage
Chunyu Zhou,*,† Jerzy A. Szpunar,† and Xiaoyu Cui‡ †
Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9,
Canada. ‡
Canadian Light Source Inc., Saskatoon, SK, S7N 2V3, Canada.
Corresponding Author Chunyu Zhou Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon SK S7N 5A9, Canada. *Email: [email protected]
S-1
Figure S1. Digital images of the prepared graphene oxide with increasing concentration from left to right.
Figure S2. (a-e) SEM and (f) TEM morphology observations of graphene sheets.
The homemade apparatus (Fig S2) is mainly equipped with a hydrogen cylinder (HY 5.0UH-T, UHP Grade 99.999%, Praxair), a pressure regulator (KPP1RSH422P2A030, Swagelok), a S-2
sample vessel (250 ml, 453HC-316-0719842151, Parr Instrument), a rupture disc (Parr Instrument), a heater (854HC, Parr Instrument), a pressure gauge (PPC5352, Winters Instrument), a temperature controller (50 °C to 1200 °C, 210/TIMER-K mode, J-KEM Scientific) with a ceramic insulated thermocouple (870 °C, XC-20-K-24, Omega) and a filter (pore size of 0.5 μm, SS-4FW-VCR-2). All tubes (SS-T2-S-028-20), valves (SS-4UG-V51-VS), connectors and fittings (gasket, 457HC2) are purchased from Swagelok. Due to the high operating pressure and potential corrosion, all reactors, valves, connectors and fittings are made of 316 stainless steel. All valves are bellows-sealed with maximum working temperature and pressure of 343 °C and 240 bar, respectively.
S-3
Figure S3. Home-made instrument for hydrogen charging process.
Figure S4. SEM morphology observation of the bare metallic Ni that prepared from hydrogen thermal treatment.
Figure S5. SEM observations of Ni/graphene composites before and after hydrogen charge: (a) Ni/graphene_0 bar and (b) Ni/graphene_60 bar.
S-4
Supporting Discussion The Scherrer analysis of the XRD broadened peaks allows the crystallite size determination of nanocrystals in solid powder with the domain size smaller than 100 nm.1–4 In the spectrum of the Ni/graphene, the crystallite size of Ni nanoparticles was measured by evaluating the Scherrer relation 𝜏 = Kλ/βcosθ to be 7 ~ 9 nm. Where: τ is the mean size of the crystallites, which may be smaller or equal to the grain size; K is a crystallite shape factor, with a value close to unity and the typical value of about 0.9; λ is the X-ray radiation wavelength of radiation [λ(Cr)=0.229 nm]; β is the line broadening of full width at half maximum (FWHM) of Ni(111) or Ni (200) in radians units; θ is the Bragg angle and the peak position in degrees.
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REFERENCE (1)
Alexander, L.; Klug, H. P. Determination of Crystallite Size with the X-Ray Spectrometer. J. Appl. Phys. 1950, 21, 137–142.
(2)
Rogério dos Santos Alves; Alex Soares de Souza, et all. The Scherrer Formula for X-Ray Particle Size Determination. Igarss 2014 2014, 56, 1–5.
(3)
Caņado, L. G.; Takai, K.; Enoki, T.; Endo, M.; Kim, Y. A.; Mizusaki, H.; Jorio, A.; Coelho, L. N.; Magalhães-Paniago, R.; Pimenta, M. A. General Equation for the Determination of the Crystallite Size La of Nanographite by Raman Spectroscopy. Appl. Phys. Lett. 2006, 88, 1–4.
(4)
Perera, S. D.; Mariano, R. G.; Vu, K.; Nour, N.; Seitz, O.; Chabal, Y.; Balkus, K. J. Hydrothermal Synthesis of Graphene-TiO 2 Nanotube Composites with Enhanced Photocatalytic Activity. 2012.
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