Pt?Au?Cu 三元核殼結構納米線的制備與結構表征

楊濤; 楊占兵; 李釩

doi:10.13374/j.issn2095-9389.2019.07.04.031

Pt?Au?Cu 三元核殼結構納米線的制備與結構表征

doi: 10.13374/j.issn2095-9389.2019.07.04.031

楊濤¹,
楊占兵^1, ,,
李釩²

1.
北京科技大學冶金與生態工程學院，北京 100083
2.
北京工業大學環境與能源工程學院，北京 100124

基金項目: 國家自然科學基金資助項目（51471027，51472009，51172007）

詳細信息

通訊作者:
E-mail：yangzhanbing@ustb.edu.cn

中圖分類號: O643.36
計量
- 文章訪問數: 1311
- HTML全文瀏覽量: 932
- PDF下載量: 22
- 被引次數: 0
出版歷程
- 收稿日期: 2019-07-04
- 刊出日期: 2019-12-01

Synthesis and structural characterization of Pt?Au?Cu ternary core-shell nanowires

1.
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
2.
College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China

More Information

Corresponding author: E-mail: yangzhanbing@ustb.edu.cn

摘要

摘要: 通過水溶液還原法在80 ℃合成Cu納米線，再利用液相還原法在低溫水溶液中將Au負載于其表面，最后通過暴露的Cu納米線與Pt前驅體鹽發生Galvanic置換反應，將Pt負載在Au?Cu納米線表面，構成Pt?Au?Cu三元核殼結構納米線。根據對樣品形貌、結構的表征和分析，探討了Pt?Au?Cu納米線的合成機理。結果表明：合成納米線物相組成為單質Cu，平均直徑約為83 nm；負載Au后的Au?Cu納米線平均直徑約為90 nm，表面附著的小顆粒為單質Au顆粒，構成了核殼結構；負載Pt后得到Pt?Au?Cu三元核殼結構納米線，平均直徑約為120 nm。Cu納米線表面Au顆粒的形成依賴于異相形核與長大機制，并遵循先層狀后島狀生長的混合生長模式。負載Pt過程中存在Pt、Cu互擴散，使得最終納米線表面多為Pt顆粒而整體則形成CuPt 合金相。
- Pt基催化劑 /
- 納米線 /
- 核殼結構 /
- 異相形核 /
- 互擴散
Abstract: Platinum-based catalysts have been widely used in fuel cells due to their excellent activity in oxygen reduction reactions. At the same time, using Pt in large quantities is costly. To solve the high cost of fuel cell catalysts, research into low-Pt-content and highly efficient catalysts with special structures has attracted considerable attention. However, conditions required for synthesis of these catalysts are highly restrictive and the synthetic methods are energy-intensive and harmful to the environment. In this study, Cu nanowires (NWs) were synthesized hydrothermally at 80 ℃. Growth of the Au shell on the Cu NWs, achieved through a liquid phase reduction method, was carried out in aqueous solution at low temperature. Finally, Pt layers were deposited on the surface of the Au?Cu NWs by Galvanic displacement between the uncovered copper NWs and chloroplatinic acid. Subsequently, Pt?Au?Cu ternary core-shell catalysts were constructed. The as-synthesized catalysts were characterized in depth using scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). The growth mechanism of the Pt?Au?Cu NWs was also explored. Results show that the phase composition of the synthetic NWs is monolithic Cu with an average diameter of about 83 nm; average diameter of the Au?Cu NWs is about 90 nm, and the small particles attached to the surface are Au. After Pt loading, the Pt?Au?Cu ternary core shell structure of the NWs is obtained with an average diameter of 120 nm. It is confirmed that the formation of the surface Au nanoparticles on the Cu NWs depends on the heterogeneous nucleation and growth mechanism, and that the growth mode conforms to the Stranski-Krastanow (S-K) mode. Pt and Cu interdiffusion exists during Pt loading, so that the surface of the NW is mostly Pt particles and the whole is a CuPt alloy phase. This study demonstrates a new strategy in synthesis of ternary core-shell NWs.
- platinum-based catalysts /
- nanowires /
- core-shell structure /
- heterogeneous nucleation /
- interdiffusion

HTML全文

圖 1 合成樣品的掃描電鏡和透射電鏡圖. (a,d) Cu納米線；(b, e) Au?Cu納米線；(c,f) Pt?Au?Cu納米線 (插圖為實際產物的照片)

Figure 1. SEM and TEM images of as-synthesized sample: (a,d) Cu nanowires；(b, e) Au?Cu nanowires；(c,f) Pt?Au?Cu nanowires (insets are photos of actual product)

下載: 全尺寸圖片幻燈片

圖 2 納米線的X射線衍射圖譜

Figure 2. X-ray diffraction patterns of as-synthesized nanowires

下載: 全尺寸圖片幻燈片

圖 3 Pt?Au?Cu納米線的高角環形暗場像(a)和元素面掃分布圖(b～d)

Figure 3. HAADF image of Pt?Au?Cu nanowires (a) and corresponding EDS mapping images (b~d)

下載: 全尺寸圖片幻燈片

圖 4 抗壞血酸作還原劑得到產物的掃描電鏡圖

Figure 4. SEM images of product obtained by using ascorbic acid as a reduction agent

下載: 全尺寸圖片幻燈片

圖 5 25 ℃時Cu?H₂O系電位pH圖

Figure 5. Pourbaix diagram of Cu?H₂O system at 25 ℃

下載: 全尺寸圖片幻燈片

圖 6 不同反應時間下的產物的透射電鏡圖(a)以及Cu納米線表面附著顆粒數量與反應時間關系圖(b)

Figure 6. TEM images of product at different reaction time (a) and relationship between the number of particles attached to the surface of Cu nanowires and reaction time (b)

下載: 全尺寸圖片幻燈片

圖 7 Cu納米線表面顆粒直徑隨時間變化圖

Figure 7. Relationship between diameter of the particle attached to surface of Cu nanowires and time variation

下載: 全尺寸圖片幻燈片

圖 8 Pt?Au?Cu納米線透射電鏡圖(a)及圖中紅色區域高分辨濾波圖(b)

Figure 8. TEM image of Pt?Au?Cu nanowires (a) and the inverse fast Fourier-filtered Fourier transformed (IFFT) image of the red box regions in Fig. 8(a)(b)

下載: 全尺寸圖片幻燈片

表 1 實驗所用試劑

Table 1. Reagents used in the experiment

試劑	分子式	純度	生產廠家
硝酸銅	Cu(NO₃)₂ ·3H₂O	分析純	西亞化學工業有限公司
氫氧化鈉	NaOH	分析純	西亞化學工業有限公司
乙二胺	C₂H₈N₂	分析純	西亞化學工業有限公司
抗壞血酸	C₆H₈O₆	優級純	西亞化學工業有限公司
水合肼	N₂H₄·xH₂O	50%~60%	Sigma-Aldrich
氯金酸	HAuCl₄·4H₂O	分析純	天津光復精細化工研究所
氯鉑酸	H₂PtCl₆·6H₂O	分析純	天津光復精細化工研究所
聚乙烯吡咯烷酮	(C₆H₉NO)_n	化學純	北京化學試劑公司
無水乙醇	C₂H₅OH	分析純	北京化工廠

下載: 導出CSV

表 2 Cu和Au的基本物理常數

Table 2. Fundamental physical constants of Cu and Au

元素	點陣常數/nm	電負性	鍵解離能/(kJ·mol^?1)
Cu	0.3615	1.9	Au?Cu: 227.1
Au	0.4078	2.4	Au?Au: 226.2

下載: 導出CSV

www.77susu.com

參考文獻(33)

[1]	Wang J Y, Wang H L, Fan Y. Techno-economic challenges of fuel cell commercialization. Engineering, 2018, 4(3): 352 doi: 10.1016/j.eng.2018.05.007
[2]	Wang Y J, Zhao N N, Fang B Z, et al. Carbon-supported Pt-based alloy electrocatalysts for the oxygen reduction reaction in polymer electrolyte membrane fuel cells: particle size, shape, and composition manipulation and their impact to activity. Chem Rev, 2015, 115(9): 3433 doi: 10.1021/cr500519c
[3]	Greeley J, Stephens I E L, Bondarenko A S, et al. Alloys of platinum and early transition metals as oxygen reduction electrocatalysts. Nature Chem, 2009, 1(7): 552 doi: 10.1038/nchem.367
[4]	Ma S Y, Li H H, Hu B C, et al. Synthesis of low Pt-based quaternary PtPdAuTe nanotubes with optimized incorporation of Pd for enhanced electrocatalytic activity. J Am Chem Soc, 2017, 139(16): 5890 doi: 10.1021/jacs.7b01482
[5]	Garlyyev B, Kratzl K, Rück M, et al. Optimizing the size of platinum nanoparticles for enhanced mass activity in the electrochemical oxygen reduction reaction. Angew Chem Int Ed, 2019, 58(28): 9596 doi: 10.1002/anie.201904492
[6]	Shao M H, Peles A, Shoemaker K. Electrocatalysis on platinum nanoparticles: particle size effect on oxygen reduction reaction activity. Nano Lett, 2011, 11(9): 3714 doi: 10.1021/nl2017459
[7]	Park J, Zhang L, Choi S I, et al. Atomic layer-by-layer deposition of platinum on palladium octahedra for enhanced catalysts toward the oxygen reduction reaction. ACS Nano, 2015, 9(3): 2635 doi: 10.1021/nn506387w
[8]	Gómez-Marín A M, Feliu J M. Oxygen reduction on nanostructured platinum surfaces in acidic media: promoting effect of surface steps and ideal response of Pt(111). Catal Today, 2015, 244: 172 doi: 10.1016/j.cattod.2014.05.009
[9]	Cui C H, Gan L, Heggen M, et al. Compositional segregation in shaped Pt alloy nanoparticles and their structural behaviour during electrocatalysis. Nature Mater, 2013, 12(8): 765 doi: 10.1038/nmat3668
[10]	Chen G Y, Kuttiyiel K A, Li M, et al. Correlating the electrocatalytic stability of platinum monolayer catalysts with their structural evolution in the oxygen reduction reaction. J Mater Chem A, 2018, 6(42): 20725 doi: 10.1039/C8TA06686H
[11]	Bao S X, Vara M, Yang X, et al. Facile synthesis of Pd@Pt_3-4l core-shell octahedra with a clean surface and thus enhanced activity toward oxygen reduction. Chem Cat Chem, 2017, 9(3): 414
[12]	Cui C H, Yu S H. Engineering interface and surface of noble metal nanoparticle nanotubes toward enhanced catalytic acitivity for fuel cell applications. Acc Chem Res, 2012, 46(7): 1427
[13]	Lu Y X, Du S F, Steinberger-Wilckens R. One-dimensional nanostructured electrocatalysts for polymer electrolyte membrane fuel cells-a review. Appl Catal B, 2016, 199: 292 doi: 10.1016/j.apcatb.2016.06.022
[14]	Zhang J T, Li C M. Nanoporous metals: fabrication strategies and advanced electrochemical applications in catalysis, sensing and energy systems. Chem Soc Rev, 2012, 41(21): 7016 doi: 10.1039/c2cs35210a
[15]	Koenigsmann C, Santulli A C, Gong K P, et al. Enhanced electrocatalytic performance of processed, ultrathin, supported Pd–Pt core–shell nanowire catalysts for the oxygen reduction reaction. J Am Chem Soc, 2011, 133(25): 9783 doi: 10.1021/ja111130t
[16]	Cherevko S, Xing X L, Chung C H. Pt and Pd decorated Au nanowires: extremely high activity of ethanol oxidation in alkaline media. Electrochim Acta, 2011, 56(16): 5771 doi: 10.1016/j.electacta.2011.04.052
[17]	Cui C H, Li H H, Liu X J, et al. Surface composition and lattice ordering-controlled activity and durability of CuPt electrocatalysts for oxygen reduction reaction. ACS Catal, 2012, 2(6): 916 doi: 10.1021/cs300058c
[18]	Niu Z Q, Cui F, Yu Y, et al. Ultrathin epitaxial Cu@Au core-shell nanowires for stable transparent conductors. J Am Chem Soc, 2017, 139(21): 7348 doi: 10.1021/jacs.7b02884
[19]	Stamenkovic V R, Mun B S, Arenz M, et al. Trends in electrocatalysis on extended and nanoscale Pt-bimetallic alloy surfaces. Nature Mater, 2007, 6(3): 241 doi: 10.1038/nmat1840
[20]	Zhang J, Sasaki K, Sutter E, et al. Stabilization of platinum oxygen-reduction electrocatalysts using gold clusters. Science, 2007, 315(5809): 220 doi: 10.1126/science.1134569
[21]	Wang C, Van der Vliet D, More K L, et al. Multimetallic Au/FePt₃ nanoparticles as highly durable electrocatalyst. Nano Lett, 2010, 11(3): 919
[22]	Rathmell A R, Wiley B J. The synthesis and coating of long, thin copper nanowires to make flexible, transparent conducting films on plastic substrates. Adv Mater, 2011, 23(41): 4798 doi: 10.1002/adma.201102284
[23]	Han M, Liu S L, Zhang L Y, et al. Synthesis of octopus-tentacle-like Cu nanowire-Ag nanocrystals heterostructures and their enhanced electrocatalytic performance for oxygen reduction reaction. ACS Appl Mater Interfaces, 2012, 4(12): 6654 doi: 10.1021/am301814y
[24]	Hong W, Wang J, Wang E. Facile synthesis of PtCu nanowires with enhanced electrocatalytic activity. Nano Res, 2015, 8(7): 2308 doi: 10.1007/s12274-015-0741-y
[25]	Peng Z M, Yang H. Designer platinum nanoparticles: control of shape, composition in alloy, nanostructure and electrocatalytic property. Nano Today, 2009, 4(2): 143 doi: 10.1016/j.nantod.2008.10.010
[26]	Xie X J, Lü K, Yan M, et al. Potential-pH chart for copper-water system and controlling pH of internal cooling water to prevent generator from corrosion. Corros Sci Prot Technol, 2007, 19(3): 162 doi: 10.3969/j.issn.1002-6495.2007.03.002 謝學軍, 呂珂, 晏敏, 等. 銅水體系電位-pH圖與發電機內冷水pH調節防腐. 腐蝕科學與防護技術, 2007, 19(3):162 doi: 10.3969/j.issn.1002-6495.2007.03.002
[27]	Yang X Z, Yang W. Metal Corrosion Electrochemical Thermodynamics: Pourbaix Diagram and Their Application. Beijing: Chemical Industry Press, 1991 楊熙珍, 楊武. 金屬腐蝕電化學熱力學: 電位-pH圖及其應用. 北京: 化學工業出版社, 1991
[28]	Goia D, Matijevi? E. Tailoring the particle size of monodispersed colloidal gold. Colloids Surf A, 1999, 146(1-3): 139 doi: 10.1016/S0927-7757(98)00790-0
[29]	Bauer E, van der Merwe J H. Structure and growth of crystalline superlattices: from monolayer to superlattice. Phys Rev B, 1986, 33(6): 3657 doi: 10.1103/PhysRevB.33.3657
[30]	Fan F R, Liu D Y, Wu Y F, et al. Epitaxial growth of heterogeneous metal nanocrystals: from gold nano-octahedra to palladium and silver nanocubes. J Am Chem Soc, 2008, 130(22): 6949 doi: 10.1021/ja801566d
[31]	Markov I V. Crystal Growth for Beginners: Fundamentals of Nucleation, Crystal Growth and Epitaxy. 3rd Ed. Singapore: World Scientific, 2016
[32]	Wang Z L, Ahmad T S, El Sayed M A. Steps, ledges and kinks on the surfaces of platinum nanoparticles of different shapes. Surf Sci, 1997, 380(2-3): 302 doi: 10.1016/S0039-6028(97)05180-7
[33]	Sarkar A, Manthiram A. Synthesis of Pt@Cu core-shell nanoparticles by galvanic displacement of Cu by Pt⁴⁺ ions and their application as electrocatalysts for oxygen reduction reaction in fuel cells. J Phys Chem C, 2010, 114(10): 4725 doi: 10.1021/jp908933r