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Chemical Reduction Synthesis and Electrochemistry of Si-Sn Nanocomposites as High-Capacity Anode for Li-Ion Batteries Kang Yao, Min Ling, Gao Liu, and Wei Tong J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.8b02066 • Publication Date (Web): 21 Aug 2018 Downloaded from http://pubs.acs.org on August 26, 2018

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The Journal of Physical Chemistry Letters

Chemical Reduction Synthesis and Electrochemistry of Si-Sn Nanocomposites as High-Capacity Anode for Li-Ion Batteries Kang Yao†, Min Ling‡, Gao Liu†, Wei Tong*† †

Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States ‡

College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China

Corresponding Author *[email protected]

ABSTRACT

Pure Sn and Si-Sn phases are successfully synthesized by a facile and scalable chemical reduction method. The as-produced Si-Sn nanocomposites exhibit excellent cycling stability, as evidenced by a reversible capacity of 700 mAh/g over 200 cycles, due to the exceptional conductivity and ductility of Sn as well as its buffering effect. More specifically, homogeneous mixing between Si and Sn during the liquid phase reaction helps reduce the maximal stress

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evolved upon electrochemical cycling by confining the expansion of electrochemically active metal component. Additionally, chemical reduction method produces small and uniform particles in the final product that are more favorable to Li+ diffusion and tolerant of mechanical stress and strain. Our work demonstrates that chemical reduction method, free of ultra-high vacuum and/or temperature, presents a new approach for the development of intermetallic metal anodes through the incorporation of various metal precursors.

TOC GRAPHICS

KEYWORDS Li-ion battery, Si-Sn anode, chemical reduction, high capacity, liquid-phase reaction Si has been extensively investigated as a promising anode for the next generation of highenergy Li-ion batteries (LIBs) in the past decade, due to its high theoretical capacity of 4,200 mAh/g for Li4.4Si, 10 times that of graphite anode used in the commercial LIBs (372 mAh/g), as well as its abundance.1-9 However, it is not viable for the practical application because of the intrinsic volume expansion of approximately 400% and subsequent contraction during the lithiation and delithiation process, respectively.10-12 Forming Si-metal alloys and/or composites,


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where Si is contained in a Li-active or inactive matrix, is an effective strategy to utilize electrochemical activity of Si while mitigating the volume change.13-21 Of numerous Si-based metal anodes, Si-Sn system is of particular interest because of several unique properties that Sn can offer compared to Si and other metals. For example, Sn is electrochemically active (993 mAh/g for Li4.4Sn) as opposed to those inactive metals, Sn is electrically conductive (9.2 × 104 S/cm at 20 ⁰C, 9 orders of magnitude higher than Si) and has good ductility. Indeed, Si-Sn nanocomposites have been prepared by various approaches, such as magnetron sputtering,21-24 mechanical milling,25-26 and annealing electrode slurry with tin dichloride precursor,27 of which Si-Sn thin film systems demonstrated the best electrochemical performance. A key challenge remains to achieve homogeneous mixing between Si and Sn, ideally at atomic level to mimic thin film system to certain extent, in order to harness all the desired merits of both metals in the composite electrodes. In this regard, facile and scalable chemical reduction method aroused our interest because it can possibly facilitate the synthesis of nanoporous metal structures in liquid phase reaction at room temperature depending on the reducing agent. For example, Cu-Sn alloys can be produced by reducing Sn and Cu salts in ethanol using sodium borohydride (NaBH4) as a reducing agent without involving any specialized equipment.28-29 Additionally, monodisperse transition metal (i.e., Mn, Ni, Cu) doping in Si nanocrystals with a well-defined metal size of ~ 2.5 nm was achieved by in situ chemical reduction of silicon and metal chlorides and demonstrated unique optical properties.30 Recently, this simple and versatile synthesis route has been demonstrated to form a variety of nanoporous metals, including both noble metals (i.e., Au, Ag) and less-noble transition metals (Co, Fe, Ni).31 Here, we report the synthesis of Si-Sn nanocomposites via chemical reduction in an aqueous solution. We demonstrate the successful synthesis of pure Si-Sn nanocomposites as well as


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homogeneous mixing of Si and Sn NPs in the final product through a complete reduction of metal salts in a liquid phase reaction. The as-produced Si-Sn nanocomposites exhibit a stable cycling behavior, a reversible capacity of 700 mAh/g being retained over 200 cycles.

Figure 1. XRD patterns of as-produced Sn and Si-Sn phases along with commercial Si, Sn and milled Si-Sn. Choice of metal precursors, reducing agents, and solvents (aqueous or organic) are critical for the chemical reduction reaction. Typically, reactivity of reactants and their solubility in solvents as well as the yield of the final products are important considerations.32 In this work, the effectiveness of chemical reduction method was initially investigated by using SnCl2 and NaBH4 as the metal precursor and reducing agent, respectively. Indeed, different kinds of reducing agents, such as sodium citrate, ascorbic acid, and hydrazine, can be used to reduce metallic tin cations, accompanied by the oxidation of reducing agent. However, hydrazine is toxic and corrosive and reduction reaction by a mild reducing agent will likely require an elevated temperature.33-34 Therefore, the strong reducing agent, NaBH4, was used to enable the chemical reduction reaction at room temperature. The X-ray diffraction (XRD) patterns of as-produced Sn and Si-Sn phases are presented in Figure 1 along with commercial Si and Sn as well as Si-Sn


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nanocomposites prepared by mechanical milling as reference. It can be seen that pure Sn phase forms by chemical reduction for only 5 min. All diffraction peaks can be well indexed to crystalline Sn with no SnCl2 residual detectable, suggesting the effectiveness of chemical reduction method in producing elemental Sn. Subsequently, chemical reduction for 5 min and 15 h was tested for the preparation of Si-Sn nanocomposites. A longer reaction duration was selected to guarantee a complete reaction (to be discussed later). Here, only Si-Sn sample prepared for 15 h is presented for the sake of clarity. The XRD pattern of the Si-Sn sample prepared by chemical reduction method is almost identical to that of milled Si-Sn, featured by the characteristic diffraction peaks of Si and Sn at the elemental state. Of note, much less pronounced Si diffraction peaks in the XRD pattern of milled Si-Sn sample are in large part due to the amorphous Si after high energy milling for an extended duration. Here, a similar amorphous feature revealed in the as-produced Si-Sn sample suggests a possible synthesis pathway to promote amorphous and/or nanostructured metals. Absence of additional diffraction peaks verifies the completion of chemical reduction with no detectable secondary reaction. Moreover, no further chemical reaction between Si and Sn is expected due to their immiscibility.


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Figure 2. SEM images of Sn and Si-Sn phases prepared by chemical reduction method. The morphology and microstructure of the as-produced samples are examined by scanning electron microscopy (SEM) (Figure 2). Both Sn and Si-Sn phases prepared by chemical reduction method exhibit uniform particle distribution with a particle size of a few hundred nanometers. A distinct feature of porous network composed of individual Sn particles is observed for the Sn sample produced by chemical reduction reaction for 5 min. A tendency in particle agglomeration with diminished porous network is revealed in the Si-Sn sample, likely resulting from a long reaction of 15 h. Energy dispersive X-ray spectroscopy (EDS) was used to examine the elemental distribution in the samples produced by chemical reduction method (Figure 3). Sn remains as a major element and shows a uniform distribution throughout the mapped area, however, Cl residual is revealed in the Sn sample after chemical reduction for 5 min, indicating the incomplete reaction of SnCl2 precursor despite its absence in the XRD pattern. Therefore, a long reaction duration of 15 h was selected to prepare the Si-Sn phase. As such, no Cl residual is detected in the as-produced Si-Sn sample. The presence of oxygen in both samples is possible in such aqueous reaction, regardless of reaction time. Moreover, uniform distribution of Si and Sn in the final product is revealed. Of note, this is distinctly different from


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milled Si-Sn sample prepared by a dry mechanical milling process, where inhomogeneous elemental distribution was induced with the presence of large agglomerated particles (tens of µm).26 As a result, improved electrochemical performance is anticipated for the samples produced by chemical reduction.

Figure 3. EDS elemental mapping of Sn and Si-Sn produced by chemical reduction method. The as-produced Si-Sn phase was subjected to galvanostatic charge/discharge testing at different electrode loadings and current densities. Representative voltage profiles of the Si-Sn phase at an electrode loading of 0.9 mg between 1.5 – 0.01 V at a current rate of C/10 are shown in Figure 4a. A large slope starts to appear around 1.2 V at the beginning of the lithiation process, but is absent in the later cycles, indicative of an irreversible reaction mostly associated to the electrolyte decomposition for solid-electrolyte interphase (SEI) formation. Subsequently, a small plateau around 0.6 V is related to the lithiation of Sn followed by an extended plateau below 0.3 V originating from lithiated Si. Overall, the as-produced Si-Sn sample exhibits a capacity of 2245 and 1380 mAh/g during the first lithiation/delithiation process, respectively, resulting in the first cycle coulombic efficiency (CE) of 61.5%. The relatively low CE is likely


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due to more side reactions originating from its porous nanostructure as the final product was obtained by harvesting the insoluble particles in a finely divided state. Also, oxygen-containing species in the final product is perhaps another contributing factor. In the subsequent cycles, the Si-Sn sample exhibits excellent cycling stability, with a reversible capacity of ~ 700 mAh/g remained after 200 cycles, which can be attributed to the homogeneous mixing of Si and Sn nanoparticles in the final product. Such advantage can be distinguished when cycling the asproduced Si-Sn sample at a higher electrode loading and current density. As noted in Figure 4b, increasing the electrode mass to ~ 1.7 mg leads to a reduction in the overall reversible capacity to ~ 500 mAh/g, suggesting the remaining limitation in Li+ and/or e- transport in the direction normal to the current collector. However, the long-term cycling performance of a similar loading does not vary significantly with applied current. All cells quickly reach a comparable capacity around 50 cycles, despite a higher initial capacity when cycled at a lower current. As discussed in the previous section, we attribute the superior performance of Si-Sn phase produced by chemical reduction method to the excellent electrical conductivity and ductility that is intrinsic to Sn metal. Note that unlike Si/C composites commonly reported in literature, no conductive carbon was added during the synthesis prior to a typical electrode formulating procedure. Therefore, uniform Si and Sn NP distribution originating from homogeneous mixing in the liquid phase reaction must occur for the Si-Sn sample produced by chemical reduction method to facilitate the role of conductive and ductile Sn. Such homogeneous elemental mixing between Si and Sn NPs in the final product is also desired in promoting the mutual buffering effect between the two active metal components in the different voltage regions. In other words, when Sn undergoes the lithiation reaction at a slightly higher voltage, accompanied by a volume expansion, Si remains inactive and serves as a buffering agent to accommodate the volume


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change resulting from the lithaition of Sn, and vice versa. Therefore, the uniform distribution of Si and Sn in the final product is important as one can produce buffering effect for the other at different states of lithiation/delithiation, resulting in the enhanced cycling performance.

Figure 4. (a) Voltage profiles and (b) cycling performance of Si-Sn prepared by chemical reduction method for 15 h. All cells were cycled at 1.5 – 0.01 V. In summary, we report the synthesis and electrochemistry of Si-Sn nanocomposite via a chemical reduction method for its potential use as LIB anode. We demonstrate chemical reduction method is effective to produce Si-Sn nanocomposites of smaller and more uniform particle size, thus promoting more homogeneous elemental distribution in the final product. The as-produced Si-Sn phase exhibits stable cycling stability by delivering a reversible capacity of 700 mAh/g over 200 cycles. The homogeneous mixing between nanostructured Si and Sn in the aqueous solution and potential benefits brought by Sn are the key factors to the superior performance. Chemical reduction approach eliminates the need of ultra-high vacuum or high temperature and liquid reaction potentially prevents particle agglomeration. Therefore, this simple and scalable approach can be extended to the production of intermetallic metal anodes for LIBs. Of particular interest is to tune the elemental composition by incorporating a variety of metal precursors and design novel electrode architectures with modified electrode surface


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through the design of synthetic processes, for example, core-shell structure by assembling metals that are less reactive and may form more robust SEI is an exceptionally interesting direction to pursue for the search of high-capacity metal anodes. Experimental Methods Commercially available SnCl2, NaBH4, and Si nanoparticles were used as precursors. SnCl2 (0.1 M) and NaBH4 (0.13 M) solution was initially prepared separately by dissolving powder precursors in DI water. Stoichiometric amount of Si NPs was added into the NaBH4 solution and ultrasonically mixed to facilitate the dispersion of Si NPs. Once Si NPs were fully dispersed, SnCl2 solution was added dropwise to the NaBH4 solution with Si NPs (Si: Sn = 2:1). The addition speed was controlled to be 0.2 mL/s and the resultant solution with colloids was mixed for designated durations, followed by carefully removing the supernatants and centrifuging the insoluble powder. The as-obtained powder was quickly washed by DI water three times and dried to completely remove water under vacuum to obtain the final product. Sn NPs were prepared to prove the effectiveness of this method according to the similar procedure described above except the addition of Si NPs. X-ray diffraction (XRD) patterns were collected using a Bruker D2-Phaser with CuKα radiation (λ = 1.54178 Å). Scanning electron microscopy (SEM) was performed on a JEOL JSM-7000F equipped with a Thermo Scientific energy dispersive Xray spectroscopy (EDS) detector. Slurries containing 80 wt% of active material, 10 wt% of carboxymethyl cellulose binder, and 10 wt% Super C-65 (Timical) were prepared by a low energy milling process for 10 h. The coated electrodes were dried under vacuum at 130 ⁰C for 12 h to completely remove the water. 2325-type coin cells were assembled using Li metal as the counter electrode and 1 M LiPF6 in ethylene carbonate: diethyl carbonate, 3:7 w/w containing 30 wt% fluoroethylene carbonate


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(FEC) (BASF) as the electrolyte inside an Ar-filled glovebox. Galvanostatic discharge and charge testing at various current densities between 0.01 V and 1.5 V was performed on a Maccor 4200 battery cycler at 30 ⁰C. 1C is defined as 3000 mA/g for this work. All the potential values are referenced to Li/Li+. AUTHOR INFORMATION Corresponding Author *Email: [email protected] Author Contributions K. Y. and M. L. contributed equally to this work. Notes The authors declare no competing financial interests. ACKNOWLEDGMENT This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DEAC02-05CH11231. REFERENCES 1.

Chan, C. K.; Peng, H. L.; Liu, G.; McIlwrath, K.; Zhang, X. F.; Huggins, R. A.; Cui, Y.,

High-Performance Lithium Battery Anodes Using Silicon Nanowires. Nat. Nanotechnol. 2008, 3, 31–35.


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2.

Page 12 of 16

Rong, J. P.; Fang, X.; Ge, M. Y.; Chen, H. T.; Xu, J.; Zhou, C. W., Coaxial Si/Anodic

Titanium Oxide/Si Nanotube Arrays for Lithium-Ion Battery Anodes. Nano Res. 2013, 6, 182– 190. 3.

Ge, M. Y.; Rong, J. P.; Fang, X.; Zhou, C. W., Porous Doped Silicon Nanowires for

Lithium Ion Battery Anode with Long Cycle Life. Nano lett. 2012, 12, 2318–2323. 4.

Liu, N.; Hu, L. B.; McDowell, M. T.; Jackson, A.; Cui, Y., Prelithiated Silicon

Nanowires as an Anode for Lithium Ion Batteries. ACS Nano 2011, 5, 6487–6493. 5.

Magasinski, A.; Dixon, P.; Hertzberg, B.; Kvit, A.; Ayala, J.; Yushin, G., High-

Performance Lithium-Ion Anodes Using a Hierarchical Bottom-up Approach. Nat. Mater. 2010, 9, 353–358. 6.

Ge, M. Y.; Rong, J. P.; Fang, X.; Zhang, A. Y.; Lu, Y. H.; Zhou, C. W., Scalable

Preparation of Porous Silicon Nanoparticles and Their Application for Lithium-Ion Battery Anodes. Nano Res. 2013, 6, 174–181. 7.

Wu, H.; Chan, G.; Choi, J. W.; Ryu, I.; Yao, Y.; McDowell, M. T.; Lee, S. W.; Jackson,

A.; Yang, Y.; Hu, L. B.; Cui, Y., Stable Cycling of Double-Walled Silicon Nanotube Battery Anodes through Solid-Electrolyte Interphase Control. Nat. Nanotechnol. 2012, 7, 310–315. 8.

Ma, D.; Cao, Z.; Hu, A., Si-Based Anode Materials for Li-Ion Batteries: A Mini Review.

Nano-Micro. Lett. 2014, 6, 347–358. 9.

Iwamura, S.; Nishihara, H.; Kyotani, T., Fast and Reversible Lithium Storage in a

Wrinkled Structure Formed from Si Nanoparticles during Lithiation/Delithiation Cycling. J. Power Sources 2013, 222, 400–409.


12

Page 13 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


10. Szczech, J. R.; Jin, S., Nanostructured Silicon for High Capacity Lithium Battery Anodes. Energy Environ. Sci. 2011, 4, 56–72. 11. Wu, H.; Cui, Y., Designing Nanostructured Si Anodes for High Energy Lithium Ion Batteries. Nano Today 2012, 7, 414–429. 12. Liu, X. H.; Zhong, L.; Huang, S.; Mao, S. X.; Zhu, T.; Huang, J. Y., Size-Dependent Fracture of Silicon Nanoparticles during Lithiation. ACS Nano 2012, 6, 1522–1531. 13. Obrovac, M.; Chevrier, V., Alloy Negative Electrodes for Li-Ion Batteries. Chem. Rev. 2014, 114, 11444–11502. 14. Hatchard, T.; Topple, J.; Fleischauer, M.; Dahn, J., Electrochemical Performance of SiAlSn Films Prepared by Combinatorial Sputtering. Electrochem. Solid-State Lett. 2003, 6, A129–A132. 15. Fleischauer, M.; Dahn, J., Combinatorial Investigations of the Si-Al-Mn System for LiIon Battery Applications. J. Electrochem. Soc. 2004, 151, A1216–A1221. 16. Fleischauer, M.; Topple, J.; Dahn, J., Combinatorial Investigations of Si-M (M = Cr + Ni, Fe, Mn) Thin Film Negative Electrode Materials. Electrochem. Solid-State Lett. 2005, 8, A137– A140. 17. Dahn, J.; Mar, R.; Fleischauer, M.; Obrovac, M., The Impact of the Addition of Rare Earth Elements to Si1-xSnx Negative Electrode Materials for Li-Ion Batteries. J. Electrochem. Soc. 2006, 153, A1211–A1220. 18. Zhang, W.-J., A Review of the Electrochemical Performance of Alloy Anodes for Lithium-Ion Batteries. J. Power Sources 2011, 196, 13–24.


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Page 14 of 16

19. Al-Maghrabi, M.; Thorne, J.; Sanderson, R.; Byers, J.; Dahn, J.; Dunlap, R., A Combinatorial Study of the Sn-Si-C System for Li-Ion Battery Applications. J. Electrochem. Soc. 2012, 159, A711–A719. 20. Al-Maghrabi, M.; Chevrier, V.; Dahn, J.; Sanderson, R.; Dunlap, R., Studies of Si-Fe-C Electrode Materials Prepared by Combinatorial Sputter Deposition. J. Electrochem. Soc. 2017, 164, A498–A507. 21. Beaulieu, L.; Hewitt, K.; Turner, R.; Bonakdarpour, A.; Abdo, A.; Christensen, L.; Eberman, K.; Krause, L.; Dahn, J., The Electrochemical Reaction of Li with Amorphous Si-Sn Alloys. J. Electrochem. Soc. 2003, 150, A149–A156. [22.

Hatchard, T.; Dahn, J., Study of the Electrochemical Performance of Sputtered Si1-xSnx

Films. J. Electrochem. Soc. 2004, 151, A1628–A1635. 23. Ahn, H.-J.; Kim, Y.-S.; Park, K.-W.; Seong, T.-Y., Use of Sn–Si Nanocomposite Electrodes for Li Rechargeable Batteries. Chem. Commun. 2005, 1, 43–45. 24. Xiao, X.; Wang, J. S.; Liu, P.; Sachdev, A. K.; Verbrugge, M. W.; Haddad, D.; Balogh, M. P., Phase-Separated Silicon–Tin Nanocomposites for Hhigh Capacity Negative Electrodes in Lithium Ion Batteries. J. Power Sources 2012, 214, 258–265. 25. Wu, J.; Zhu, Z.; Zhang, H.; Fu, H.; Li, H.; Wang, A.; Zhang, H., A Novel Si/Sn Composite with Entangled Ribbon Structure as Anode Materials for Lithium Ion Battery. Sci. Rep. 2016, 6, 29356.


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Page 15 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


26. Xu, J.; Ling, M.; Terborg, L.; Zhao, H.; Qiu, F.; Urban, J. J.; Kostecki, R.; Liu, G.; Tong, W., Facile Synthesis and Electrochemistry of Si-Sn-C Nanocomposites for High-Energy Li-Ion Batteries. J. Electrochem.l Soc. 2017, 164, A1378–A1383. 27. Zhong, L.; Beaudette, C.; Guo, J.; Bozhilov, K.; Mangolini, L., Tin Nanoparticles as an Effective Conductive Additive in Silicon Anodes. Sci. Rep. 2016, 6, 30952. 28. Wolfenstine, J.; Campos, S.; Foster, D.; Read, J.; Behl, W. K., Nano-Scale Cu6Sn5 Anodes. J. Power Sources 2002, 109, 230-233. 29. Smith, N.; Sekido, N.; Perepezko, J.; Ellis, A.; Crone, W., Synthesis of Dual Phase Bronze Alloys from Elemental Nanoparticle Constituents. Scripta Mater. 2004, 51, 423–426. 30. McVey, B. F.; Butkus, J.; Halpert, J. E.; Hodgkiss, J. M.; Tilley, R. D., Solution Synthesis and Optical Properties of Transition-Metal-Doped Silicon Nanocrystals. J. Phys. Chem. Lett. 2015, 6, 1573–1576. 31. Coaty, C.; Zhou, H.; Liu, H.; Liu, P., A Scalable Synthesis Pathway to Nanoporous Metal Structures. ACS Nano 2018, 12, 432–440. 32. Smith, M. B., Reduction. In Organic Synthesis (Third Edition); Smith, M. B., Ed.; Academic Press: Oxford, 2010; pp 347-490. 33. Roopan, S. M.; Elango, G., Self-Assembly of Transition Metal Nanoparticles Using Marine Sources. In Fabrication and Self-Assembly of Nanobiomaterials; Grumezescu, A. M., Ed.; William Andrew Publishing: 2016; pp 459-483.


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34. Warner, J. H.; Schäffel, F.; Bachmatiuk, A.; Rümmeli, M. H., Methods for Obtaining Graphene. In Graphene; Warner, J. H.; Schäffel, F.; Bachmatiuk, A.; Rümmeli, M. H., Eds.; Elsevier: 2013; pp 129-228.


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