Journal Home > Volume 11 , Issue 6
Nano Research 2018, 11(6): 3132-3144 https://doi.org/10.1007/s12274-018-1975-2
Research Article | Issue | Published: 22 May 2018

A versatile method for the encapsulation of various non-precious metal nanoparticles inside single-walled carbon nanotubes

Show Author's Information Tingting Cui1,2,  Xiulian Pan1( ),  Jinhu Dong1,2,  Shu Miao1,  Dengyun Miao1,  Xinhe Bao1( )
State Key Laboratory of CatalysisDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China
University of Chinese Academy of SciencesBeijing100049China
Keywords:
nanoparticles, encapsulation, confinement effect, single-walled carbon nanotubes, non-precious metals
Cite this article:
Cui T, Pan X, Dong J, et al. A versatile method for the encapsulation of various non-precious metal nanoparticles inside single-walled carbon nanotubes. Nano Research, 2018, 11(6): 3132-3144. https://doi.org/10.1007/s12274-018-1975-2
Download citation
EndNote(RIS)
BibTeX

572

Views

15

Downloads

Citations

18

Crossref

N/A

WoS

17

Scopus

0

CSCD

Abstract Full text Electronic supplementary material About this article

We present a facile and versatile method for introducing various non-precious metal nanoparticles (NPs) in small nanotubes, such as single-walled carbon nanotubes (SWNTs), including 3d-metals (V, Mn, Fe and Co), 4d-metals (Mo), and 5d-metals (W). This is realized by oxidizing encapsulated cycloalkene metal carbonyl complexes below their sublimation temperatures. This novel technique is significant because it avoids the diffusion and deposition of metal species on the outer walls of nanotubes, which has been challenging to achieve using the conventional filling methods. High-resolution transmission electron microscopy (HRTEM), high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and X-ray photoelectron spectroscopy (XPS) analyses revealed high filling efficiencies (> 95% SWNTs filled with metal NPs). This method also provides a unique approach to fabricate highly dispersed and uniform SWNT–metal nanoparticle encapsulates with lower valence states, which are often not stable in the bulk.


menu
Abstract
Full text
Outline
Electronic supplementary material
About this article

A versatile method for the encapsulation of various non-precious metal nanoparticles inside single-walled carbon nanotubes

Show Author's information Tingting Cui1,2, Xiulian Pan1( ), Jinhu Dong1,2, Shu Miao1, Dengyun Miao1, Xinhe Bao1( )
State Key Laboratory of CatalysisDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China
University of Chinese Academy of SciencesBeijing100049China

Abstract

We present a facile and versatile method for introducing various non-precious metal nanoparticles (NPs) in small nanotubes, such as single-walled carbon nanotubes (SWNTs), including 3d-metals (V, Mn, Fe and Co), 4d-metals (Mo), and 5d-metals (W). This is realized by oxidizing encapsulated cycloalkene metal carbonyl complexes below their sublimation temperatures. This novel technique is significant because it avoids the diffusion and deposition of metal species on the outer walls of nanotubes, which has been challenging to achieve using the conventional filling methods. High-resolution transmission electron microscopy (HRTEM), high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and X-ray photoelectron spectroscopy (XPS) analyses revealed high filling efficiencies (> 95% SWNTs filled with metal NPs). This method also provides a unique approach to fabricate highly dispersed and uniform SWNT–metal nanoparticle encapsulates with lower valence states, which are often not stable in the bulk.

Keywords: nanoparticles, encapsulation, confinement effect, single-walled carbon nanotubes, non-precious metals

References(78)

1

Monthioux, M.; Flahaut, E.; Cleuziou, J. P. Hybrid carbon nanotubes: Strategy, progress, and perspectives. J. Mater. Res. 2006, 21, 2774-2793.
DOI Google Scholar
2

Ilie, A.; Crampin, S.; Karlsson, L.; Wilson, M. Repair and stabilization in confined nanoscale systems—Inorganic nanowires within single-walled carbon nanotubes. Nano Res. 2012, 5, 833-844.
DOI Google Scholar
3

Shi, L.; Sheng, L. M.; Yu, L. M.; An, K.; Ando, Y.; Zhao, X. L. Ultra-thin double-walled carbon nanotubes: A novel nanocontainer for preparing atomic wires. Nano Res. 2011, 4, 759-766.
DOI Google Scholar
4

Kitaura, R.; Ogawa, D.; Kobayashi, K.; Saito, T.; Ohshima, S.; Nakamura, T.; Yoshikawa, H.; Awaga, K.; Shinohara, H. High yield synthesis and characterization of the structural and magnetic properties of crystalline Ercl3 nanowires in single-walled carbon nanotube templates. Nano Res. 2008, 1, 152-157.
DOI Google Scholar
5

Pan, X. L.; Bao, X. H. The effects of confinement inside carbon nanotubes on catalysis. Acc. Chem. Res. 2011, 44, 553-562.
DOI Google Scholar
6

Serp, P.; Castillejos, E. Catalysis in carbon nanotubes. Chemcatchem 2010, 2, 41-47.
DOI Google Scholar
7

Lota, G.; Frackowiak, E.; Mittal, J.; Monthioux, M. High performance supercapacitor from chromium oxide-nanotubes based electrodes. Chem. Phys. Lett. 2007, 434, 73-77.
DOI Google Scholar
8

Su, D. S.; Centi, G. A perspective on carbon materials for future energy application. J. Energy Chem. 2013, 22, 151-173.
DOI Google Scholar
9

Hatakeyama, R.; Li, Y. F. Synthesis and electronic-property control of Cs-encapsulated single- and double-walled carbon nanotubes by plasma ion irradiation. J. Appl. Phys. 2007, 102, 034309.
DOI Google Scholar
10

Sitharaman, B.; Kissell, K. R.; Hartman, K. B.; Tran, L. A.; Baikalov, A.; Rusakova, I.; Sun, Y.; Khant, H. A.; Ludtke, S. J.; Chiu, W. et al. Superparamagnetic gadonanotubes are high-performance mri contrast agents. Chem. Commun. 2005, 3915-3917.
DOI Google Scholar
11

Sithararnan, B.; Wilson, L. J. Gadonanotubes as new high-performance MRI contrast agents. Int. J. Nanomedicine 2006, 1, 291-295.
Google Scholar
12

Britz, D. A.; Khlobystov, A. N. Noncovalent interactions of molecules with single walled carbon nanotubes. Chem. Soc. Rev. 2006, 35, 637-659.
DOI Google Scholar
13

Miners, S. A.; Rance, G. A.; Khlobystov, A. N. Chemical reactions confined within carbon nanotubes. Chem. Soc. Rev. 2016, 45, 4727-4746.
DOI Google Scholar
14

Botos, A.; Biskupek, J.; Chamberlain, T. W.; Rance, G. A.; Stoppiello, C. T.; Sloan, J.; Liu, Z.; Suenaga, K.; Kaiser, U.; Khlobystov, A. N. Carbon nanotubes as electrically active nanoreactors for multi-step inorganic synthesis: Sequential transformations of molecules to nanoclusters and nanoclusters to nanoribbons. J. Am. Chem. Soc. 2016, 138, 8175-8183.
DOI Google Scholar
15

Kharlamova, M. V.; Kramberger, C.; Saito, T.; Sato, Y.; Suenaga, K.; Pichler, T.; Shiozawa, H. Chirality-dependent growth of single-wall carbon nanotubes as revealed inside nano-test tubes. Nanoscale 2017, 9, 7998-8006.
DOI Google Scholar
16

Stoppiello, C. T.; Biskupek, J.; Li, Z. Y.; Rance, G. A.; Botos, A.; Fogarty, R. M.; Bourne, R. A.; Yuan, J.; Lovelock, K. R. J.; Thompson, P. et al. A one-pot-one-reactant synthesis of platinum compounds at the nanoscale. Nanoscale 2017, 9, 14385-14394.
DOI Google Scholar
17

Xiao, J. P.; Pan, X. L.; Zhang, F.; Li, H. B.; Bao, X. H. Size-dependence of carbon nanotube confinement in catalysis. Chem. Sci. 2017, 8, 278-283.
DOI Google Scholar
18

Ajayan, P. M.; Ebbesen, T. W.; Ichihashi, T.; Iijima, S.; Tanigaki, K.; Hiura, H. Opening carbon nanotubes with oxygen and implications for filling. Nature 1993, 362, 522-525.
DOI Google Scholar
19

Saito, Y.; Yoshikawa, T. Bamboo-shaped carbon tube filled partially with nickel. J. Cryst. Growth 1993, 134, 154-156.
DOI Google Scholar
20

Seraphin, S.; Zhou, D.; Jiao, J.; Withers, J. C.; Loutfy, R. Yttrium carbide in nanotubes. Nature 1993, 362, 503.
DOI Google Scholar
21

Tsang, S. C.; Chen, Y. K.; Harris, P. J. F.; Green, M. L. H. A simple chemical method of opening and filling carbon nanotubes. Nature 1994, 372, 159-162.
DOI Google Scholar
22

Sloan, J.; Cook, J.; Green, M. L. H.; Hutchison, J. L.; Tenne, R. Crystallisation inside fullerene related structures. J. Mater. Chem. 1997, 7, 1089-1095.
DOI Google Scholar
23

Ugarte, D.; Stöckli, T.; Bonard, J. M.; Chatelain, A.; de Heer, W. A. Filling carbon nanotubes. Appl. Phys. A: Mater. Sci. Process 1998, 67, 101-105.
DOI Google Scholar
24

Pham-Huu, C.; Keller, N.; Estournes, C.; Ehret, G.; Ledoux, M. J. Synthesis of CoFe2O4 nanowire in carbon nanotubes. A new use of the confinement effect. Chem. Commun. 2002, 1882-1883.
DOI Google Scholar
25

Fröhlich, T.; Scharff, P.; Schliefke, W.; Romanus, H.; Gupta, V.; Siegmund, C.; Ambacher, O.; Spiess, L. Insertion of C60 into multi-wall carbon nanotubes—A synthesis of C60@mwcnt. Carbon 2004, 42, 2759-2762.
DOI Google Scholar
26

Kim, B. M.; Qian, S. Z.; Bau, H. H. Filling carbon nanotubes with particles. Nano Lett. 2005, 5, 873-878.
DOI Google Scholar
27

La Torre, A.; Rance, G. A.; El Harfi, J.; Li, J. N.; Irvine, D. J.; Brown, P. D.; Khlobystov, A. N. Transport and encapsulation of gold nanoparticles in carbon nanotubes. Nanoscale 2010, 2, 1006-1010.
DOI Google Scholar
28

Liao, G. M.; Pan, Y. Y.; Wu, Q.; Li, S. Y.; Weng, Y. Y.; Zhang, X. H.; Yang, Z. H.; Guo, J.; Chen, M. Z.; Tang, M. H. et al. A novel method to encapsulate a Au nanorod array in 15 nm radius multiwalled carbon nanotubes. Nanoscale 2014, 6, 14872-14876.
DOI Google Scholar
29

Sloan, J.; Hammer, J.; Zwiefka-Sibley, M.; Green, M. L. H.; Sloan, J. The opening and filling of single walled carbon nanotubes (SWTs). Chem. Commun. 1998, 347-348.
DOI Google Scholar
30

Sloan, J.; Wright, D. M.; Bailey, S.; Brown, G.; York, A. P. E.; Coleman, K. S.; Green, M. L. H.; Sloan, J.; Wright, D. M.; Hutchison, J. L. et al. Capillarity and silver nanowire formation observed in single walled carbon nanotubes. Chem. Commun. 1999, 699-700.
DOI Google Scholar
31

Govindaraj, A.; Satishkumar, B. C.; Nath, M.; Rao, C. N. R. Metal nanowires and intercalated metal layers in single-walled carbon nanotube bundles. Chem. Mater. 2000, 12, 202-205.
DOI Google Scholar
32

Zhang, H. B.; Pan, X. L.; Bao, X. H. Facile filling of metal particles in small carbon nanotubes for catalysis. J. Energy Chem. 2013, 22, 251-256.
DOI Google Scholar
33

Mittal, J.; Monthioux, M.; Allouche, H.; Stephan, O. Room temperature filling of single-wall carbon nanotubes with chromium oxide in open air. Chem. Phys. Lett. 2001, 339, 311-318.
DOI Google Scholar
34

Borowiak-Palen, E.; Bachmatiuk, A.; Rüemmeli, M. H.; Gemming, T.; Pichler, T.; Kalenczuk, R. J. Iron filled singlewalled carbon nanotubes—Synthesis and characteristic properties. Phys. Status Solidi B 2006, 243, 3277-3280.
DOI Google Scholar
35

Borowiak-Palen, E.; Mendoza, E.; Bachmatiuk, A.; Rummeli, M. H.; Gemming, T.; Nogues, J.; Skumryev, V.; Kalenczuk, R. J.; Pichler, T.; Silva, S. R. P. Iron filled single-wall carbon nanotubes—A novel ferromagnetic medium. Chem. Phys. Lett. 2006, 421, 129-133.
DOI Google Scholar
36

Zoberbier, T.; Chamberlain, T. W.; Biskupek, J.; Suyetin, M.; Majouga, A. G.; Besley, E.; Kaiser, U.; Khlobystov, A. N. Investigation of the interactions and bonding between carbon and group viii metals at the atomic scale. Small 2016, 12, 1649-1657.
DOI Google Scholar
37

Loebick, C. Z.; Majewska, M.; Ren, F.; Haller, G. L.; Pfefferle, L. D. Fabrication of discrete nanosized cobalt particles encapsulated inside single-walled carbon nanotubes. J. Phys. Chem. C 2010, 114, 11092-11097.
DOI Google Scholar
38

Cleuziou, J. -P.; Wernsdorfer, W.; Ondarçuhu, T.; Monthioux, M. Electrical detection of individual magnetic nanoparticles encapsulated in carbon nanotubes. ACS Nano 2011, 5, 2348-2355.
DOI Google Scholar
39

Hao, J.; Lian, Y. F.; Guan, L. H.; Yue, D. M.; Guo, X. H.; Zhao, S. X.; Zhao, Y. L.; Ibrahim, K.; Wang, J. O.; Qian, H. J. et al. Supercritical synthesis and characterization of SWNT-based one dimensional nanomaterials. Nanoscale 2011, 3, 3103-3108.
DOI Google Scholar
40

Kharlamova, M. V.; Niu, J. J. New method of the directional modification of the electronic structure of single-walled carbon nanotubes by filling channels with metallic copper from a liquid phase. JETP Lett. 2012, 95, 314-319.
DOI Google Scholar
41

Muramatsu, H.; Hayashi, T.; Kim, Y. A.; Shimamoto, D.; Endo, M.; Terrones, M.; Dresselhaus, M. S. Synthesis and isolation of molybdenum atomic wires. Nano Lett. 2008, 8, 237-240.
DOI Google Scholar
42

Chamberlain, T. W.; Zoberbier, T.; Biskupek, J.; Botos, A.; Kaiser, U.; Khlobystov, A. N. Formation of uncapped nanometre-sized metal particles by decomposition of metal carbonyls in carbon nanotubes. Chem. Sci. 2012, 3, 1919-1924.
DOI Google Scholar
43

Zoberbier, T.; Chamberlain, T. W.; Biskupek, J.; Kuganathan, N.; Eyhusen, S.; Bichoutskaia, E.; Kaiser, U.; Khlobystov, A. N. Interactions and reactions of transition metal clusters with the interior of single-walled carbon nanotubes imaged at the atomic scale. J. Am. Chem. Soc. 2012, 134, 3073-3079.
DOI Google Scholar
44

Chamberlain, T. W.; Earley, J. H.; Anderson, D. P.; Khlobystov, A. N.; Bourne, R. A. Catalytic nanoreactors in continuous flow: Hydrogenation inside single-walled carbon nanotubes using supercritical CO2. Chem. Commun. 2014, 50, 5200-5202.
DOI Google Scholar
45

Sinitsa, A. S.; Chamberlain, T. W.; Zoberbier, T.; Lebedeva, I. V.; Popov, A. M.; Knizhnik, A. A.; McSweeney, R. L.; Biskupek, J.; Kaiser, U.; Khlobystov, A. N. Formation of nickel clusters wrapped in carbon cages: Toward new endohedral metallofullerene synthesis. Nano Lett. 2017, 17, 1082-1089.
DOI Google Scholar
46

Li, Y. F.; Hatakeyama, R.; Kaneko, T.; Izumida, T.; Okada, T.; Kato, T. Synthesis and electronic properties of ferrocene-filled double-walled carbon nanotubes. Nanotechnology 2006, 17, 4143-4147.
DOI Google Scholar
47

Shiozawa, H.; Pichler, T.; Grüneis, A.; Pfeiffer, R.; Kuzmany, H.; Liu, Z.; Suenaga, K.; Kataura, H. A catalytic reaction inside a single-walled carbon nanotube. Adv. Mater. 2008, 20, 1443-1449.
DOI Google Scholar
48

Briones-Leon, A.; Ayala, P.; Liu, X. J.; Yanagi, K.; Weschke, E.; Eisterer, M.; Jiang, H.; Kataura, H.; Pichler, T.; Shiozawa, H. Orbital and spin magnetic moments of transforming one-dimensional iron inside metallic and semiconducting carbon nanotubes. Phys. Rev. B 2013, 87, 195435.
DOI Google Scholar
49

McSweeney, R. L.; Chamberlain, T. W.; Davies, E. S.; Khlobystov, A. N. Single-walled carbon nanotubes as nano-electrode and nano-reactor to control the pathways of a redox reaction. Chem. Commun. 2014, 50, 14338-14340.
DOI Google Scholar
50

Chiang, I. W.; Brinson, B. E.; Huang, A. Y.; Willis, P. A.; Bronikowski, M. J.; Margrave, J. L.; Smalley, R. E.; Hauge, R. H. Purification and characterization of single-wall carbon nanotubes (SWNTs) obtained from the gas-phase decomposition of CO (HiPco process). J. Phys. Chem. B 2001, 105, 8297-8301.
DOI Google Scholar
51

Ziegler, K. J.; Gu, Z. N.; Peng, H. Q.; Flor, E. L.; Hauge, R. H.; Smalley, R. E. Controlled oxidative cutting of single-walled carbon nanotubes. J. Am. Chem. Soc. 2005, 127, 1541-1547.
DOI Google Scholar
52

Smith, B. W.; Luzzi, D. E. Formation mechanism of fullerene peapods and coaxial tubes: A path to large scale synthesis. Chem. Phys. Lett. 2000, 321, 169-174.
DOI Google Scholar
53

Li, Y. F.; Hatakeyama, R.; Shishido, J.; Kato, T.; Kaneko, T. Air-stable p-n junction diodes based on single-walled carbon nanotubes encapsulating Fe nanoparticles. Appl. Phys. Lett. 2007, 90, 173127.
DOI Google Scholar
54

Chen, W.; Pan, X. L.; Bao, X. H. Tuning of redox properties of iron and iron oxides via encapsulation within carbon nanotubes. J. Am. Chem. Soc. 2007, 129, 7421-7426.
DOI Google Scholar
55

Chen, W.; Fan, Z. L.; Zhang, B.; Ma, G. J.; Takanabe, K.; Zhang, X. X.; Lai, Z. P. Enhanced visible-light activity of titania via confinement inside carbon nanotubes. J. Am. Chem. Soc. 2011, 133, 14896-14899.
DOI Google Scholar
56

Dresselhaus, M. S.; Dresselhaus, G.; Saito, R.; Jorio, A. Raman spectroscopy of carbon nanotubes. Phys. Rep. 2005, 409, 47-99.
DOI Google Scholar
57

Kumari, L.; Ma, Y. -R.; Tsai, C. -C.; Lin, Y. -W.; Wu, S. Y.; Cheng, K. -W.; Liou, Y. X-ray diffraction and Raman scattering studies on large-area array and nanobranched structure of 1D MoO2 nanorods. Nanotechnology 2007, 18, 115717.
DOI Google Scholar
58

Fukata, N.; Oshima, T.; Murakami, K.; Kizuka, T.; Tsurui, T.; Ito, S. Phonon confinement effect of silicon nanowires synthesized by laser ablation. Appl. Phys. Lett. 2005, 86, 213112.
DOI Google Scholar
59

Parker, J. C.; Siegel, R. W. Raman microprobe study of nanophase TiO2 and oxidation-induced spectral changes. J. Mater. Res. 1990, 5, 1246-1252.
DOI Google Scholar
60

Xiao, J. P.; Pan, X. L.; Guo, S. J.; Ren, P. J.; Bao, X. H. Toward fundamentals of confined catalysis in carbon nanotubes. J. Am. Chem. Soc. 2015, 137, 477-482.
DOI Google Scholar
61

McIntyre, N. S.; Johnston, D. D.; Coatsworth, L. L.; Davidson, R. D.; Brown, J. R. X-ray photoelectron spectroscopic studies of thin film oxides of cobalt and molybdenum. Surf. Interface Anal. 1990, 15, 265-272.
DOI Google Scholar
62

López-Carreño, L. D.; Benı́tez, G.; Viscido, L.; Heras, J. M.; Yubero, F.; Espinós, J. P.; González-Elipe, A. R. Different oxidation states of polycrystalline molybdenum treated by O2-plasma or O2-ion bombardment. Surf. Sci. 1998, 402-404, 174-177.
DOI Google Scholar
63

Biesinger, M. C.; Payne, B. P.; Grosvenor, A. P.; Lau, L. W. M.; Gerson, A. R.; Smart, R. S. C. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni. Appl. Surf. Sci. 2011, 257, 2717-2730.
DOI Google Scholar
64

Yue, C. C.; Zhu, X. C.; Rigutto, M.; Hensen, E. Acid catalytic properties of reduced tungsten and niobium-tungsten oxides. Appl. Catal. B: Environ. 2015, 163, 370-381.
DOI Google Scholar
65

Silversmit, G.; Depla, D.; Poelman, H.; Marin, G. B.; De Gryse, R. Determination of the V2p XPS binding energies for different vanadium oxidation states (V5+ to V0+). J. Electron. Spectrosc. Relat. Phenom. 2004, 135, 167-175.
DOI Google Scholar
66

Peña, D. A.; Uphade, B. S.; Smirniotis, P. G. TiO2-supported metal oxide catalysts for low-temperature selective catalytic reduction of NO with NH3: I. Evaluation and characterization of first row transition metals. J. Catal. 2004, 221, 421-431.
DOI Google Scholar
67

Lin, T. -C.; Seshadri, G.; Kelber, J. A. A consistent method for quantitative XPS peak analysis of thin oxide films on clean polycrystalline iron surfaces. Appl. Surf. Sci. 1997, 119, 83-92.
DOI Google Scholar
68

Long, M. C.; Cai, W. M.; Cai, J.; Zhou, B. X.; Chai, X. Y.; Wu, Y. H. Efficient photocatalytic degradation of phenol over Co3O4/BiVO4 composite under visible light irradiation. J. Phys. Chem. B 2006, 110, 20211-20216.
DOI Google Scholar
69

Morales, F.; de Groot, F. M. F.; Gijzeman, O. L. J.; Mens, A.; Stephan, O.; Weckhuysen, B. M. Mn promotion effects in Co/TiO2 fischer-tropsch catalysts as investigated by xps and STEM-EELS. J. Catal. 2005, 230, 301-308.
DOI Google Scholar
70

Zhang, F.; Pan, X. L.; Hu, Y. F.; Yu, L.; Chen, X. Q.; Jiang, P.; Zhang, H. B.; Deng, S. B.; Zhang, J.; Bolin, T. B. et al. Tuning the redox activity of encapsulated metal clusters via the metallic and semiconducting character of carbon nanotubes. Proc. Natl. Acad. Sci. USA 2013, 110, 14861-14866.
DOI Google Scholar
71

Chen, W. F.; Wang, C. H.; Sasaki, K.; Marinkovic, N.; Xu, W.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R. Highly active and durable nanostructured molybdenum carbide electrocatalysts for hydrogen production. Energy Environ. Sci. 2013, 6, 943-951.
DOI Google Scholar
72

Youn, D. H.; Han, S.; Kim, J. Y.; Kim, J. Y.; Park, H.; Choi, S. H.; Lee, J. S. Highly active and stable hydrogen evolution electrocatalysts based on molybdenum compounds on carbon nanotube-graphene hybrid support. ACS Nano 2014, 8, 5164-5173.
DOI Google Scholar
73

Šljukić, B.; Vujković, M.; Amaral, L.; Santos, D. M. F.; Rocha, R. P.; Sequeira, C. A. C.; Figueiredo, J. L. Carbon-supported Mo2C electrocatalysts for hydrogen evolution reaction. J. Mater. Chem. A 2015, 3, 15505-15512.
DOI Google Scholar
74

Shi, L.; Rohringer, P.; Suenaga, K.; Niimi, Y.; Kotakoski, J.; Meyer, J. C.; Peterlik, H.; Wanko, M.; Cahangirov, S.; Rubio, A. et al. Confined linear carbon chains as a route to bulk carbyne. Nat. Mater. 2016, 15, 634-639.
DOI Google Scholar
75

Yang, F. K.; Sliozberg, K.; Antoni, H.; Xia, W.; Muhler, M. MoxC/CNT composites as active electrocatalysts for the hydrogen evolution reaction under alkaline conditions. Electroanalysis 2016, 28, 2293-2296.
DOI Google Scholar
76

McIntyre, N. S.; Zetaruk, D. G. X-ray photoelectron spectroscopic studies of iron oxides. Anal. Chem. 1977, 49, 1521-1529.
DOI Google Scholar
77

Karim, A. M.; Su, Y.; Engelhard, M. H.; King, D. L.; Wang, Y. Catalytic roles of Co0 and Co2+ during steam reforming of ethanol on Co/MgO catalysts. ACS Catal. 2011, 1, 279-286.
DOI Google Scholar
78

Turchanin, M. A.; Agraval, P. G. Cohesive energy, properties, and formation energy of transition metal alloys. Powder Metall. Met. Ceram. 2008, 47, 26-39.
DOI Google Scholar
File
12274_2018_1975_MOESM1_ESM.pdf (1.8 MB)
Publication history
Copyright
Acknowledgements

Publication history

Received: 30 October 2017
Revised: 22 December 2017
Accepted: 28 December 2017
Published: 22 May 2018
Issue date: June 2018

Copyright

© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Acknowledgements

Acknowledgements

This work was financially supported by the Ministry of Science and Technology of China (No. 2016YFA0202803), and the National Natural Science Foundation of China (Nos. 21425312 and 21621063). We thank Dr. Haobo Li for help in drawing the scheme and Dr. Tie Yu for fruitful discussions.

Return