•  
  •  
 

Corresponding Author

Shi-gang SUN(sgsun@xmu.edu.cn)

Abstract

Nanostructured CoPt alloy thin film was deposited on glassy carbon substrate (denoted as CoPt/GC) under cyclic voltammetric conditions. SEM studies demonstrated that the CoPt/GC was composed of nonuniform nanoparticles with an average size of 139 nm. The composition of the CoPt/GC was analyzed by energy dispersive X-ray spectroscopy (EDS), which depicts a Co:Pt ratio of ca. 3:5. In situ FTIR spectroscopy employing CO adsorption as a probe reaction revealed that the CoPt/GC exhibits abnormal infrared effects (AIREs). The unique anomalous IR features of CO adsorbed (COad) on CoPt/GC consist in the complete inversion of the COad IR bands, the significant enhancement of IR absorption of COad, and the broadening of the COad IR bands. The current investigation has extended the study of AIREs to nanomaterials of alloy of iron family and Pt group, which is of great importance to reveal the relationship among peculiar optical properties and surface composition, structure of nanomaterials, and shed valuable insights into understanding the nature of anomalous IR properties.

Graphical Abstract

Keywords

CoPt alloy, thin film, abnormal infrared effects, in situ FTIRS

Publication Date

2014-10-28

Online Available Date

2014-03-17

Revised Date

2014-03-12

Received Date

2013-12-12

References

[1] Travitsky N, Ripenbein T, Golodnitsky D, et al. Pt-, PtNi- and PtCo-supported catalysts for oxygen reduction in PEM fuel cells[J]. Journal of Power Sources, 2006, 161(2): 782-789.
[2] Shevchenko E V, Talapin D V, Schnablegger H, et al. Study of nucleation and growth in the organometallic synthesis of magnetic alloy nanocrystals: The role of nucleation rate in size control of CoPt3 nanocrystals[J]. Journal of the American Chemical Society, 2003, 125(30): 9090-9101.
[3] Aguilera-Granja F, Longo R C, Gallego L J, et al. Structural and magnetic properties of X12Y (X, Y = Fe, Co, Ni, Ru, Rh, Pd, and Pt) nanoalloys[J]. Journal of Chemical Physics, 2010, 132(18): 184507.
[4] Hwang S J, Kim S K, Lee J G, et al. Role of electronic perturbation in stability and activity of Pt-based alloy nanocatalysts for oxygen reduction[J]. Journal of the American Chemical Society, 2012, 134(48): 19508-19511.
[5] Xu C, Sun F, Gao H, et al. Nanoporous platinum-cobalt alloy for electrochemical sensing for ethanol, hydrogen peroxide, and glucose[J]. Analytica Chimica Acta, 2013, 780: 20-27.
[6] Lu G Q, Sun S G, Chen S P, et al. Electrode processes VII[C]. Wieckowski A, Itaya K, eds., The Electrochemical Society, Inc., 1996: Proceedings PV 96, 136.
[7] Lu G Q, Sun S G, Chen S P, et al. Novel properties of dispersed Pt and Pd thin layers supported on GC for CO adsorption studied using in situ MS-FTIR reflection spectroscopy[J]. Journal of Electroanalytical Chemistry, 1997, 421(1/2): 19-23.
[8] Lu G Q, Sun S G, Cai L R, et al. In situ FTIR spectroscopic studies of adsorption of CO, SCN-, and poly(o-phenylenediamine) on electrodes of nanometer thin films of Pt, Pd, and Rh: Abnormal infrared effects (AIREs)[J]. Langmuir, 2000, 16(2): 778-786.
[9] Zheng M S, Sun S G. In situ FTIR spectroscopic studies of CO adsorption on electrodes with nanometer-scale thin films of ruthenium in sulfuric acid solutions[J]. Journal of Electroanalytical Chemistry, 2001, 500(1/2): 223-232.
[10] Wang H C, Sun S G, Yan J W, et al. In situ STM studies of electrochemical growth of nanostructured Ni films and their anomalous IR properties[J]. Journal of Physical Chemistry B, 2005, 109(10): 4309-4316.
[11] Chen Q S, Sun S G, Yan J W, et al. Electrochemical preparation and structural characterization of Co thin films and their anomalous IR properties[J]. Langmuir, 2006, 22(25): 10575-10583.
[12] Chen Z, Sun S G, Ding N, et al. Abnormal infrared effects of nanometer scale thin film material of PtPd alloy in CO adsorption[J]. Chinese Science Bulletin, 2001, 46(17): 1439-1442.
[13] Chen Q S, Zhou Z Y, Guo G C, et al. Electrodeposition of nanostructured CoNi thin films and their anomalous infrared properties[J]. Electrochimica Acta, 2013, 113: 694-705.
[14] Lin W F, Sun S G. In situ FTIRS investigations of surface processes of Rh electrode--novel observation of geminal adsorbates of carbon monoxide on Rh electrode in acid solution[J]. Electrochimica Acta, 1996, 41(6): 803-809.
[15] Cuesta A, Gutierrez C. Study by Fourier transform infrared spectroscopy of the adsorption of carbon monoxide on a cobalt electrode at pH 3-14[J]. Langmuir, 1998, 14(12): 3390-3396.
[16] Chen Q S, Sun S G, Zhou Z Y, et al. CoPt nanoparticles and their catalytic properties in electrooxidation of CO and CH(3)OH studied by in situ FTIRS[J]. Physical Chemistry Chemical Physics, 2008, 10(25): 3645-3654.
[17] Zheng M S, Sun S G, Chen S P. Abnormal infrared effects and electrocatalytic properties of nanometer scale thin film of PtRu alloys for CO adsorption and oxidation[J]. Journal of Applied Electrochemistry, 2001, 31(7): 749-757.
[18] Chen W, Sun S G, Zhou Z Y, et al. IR optical properties of Pt nanoparticles and their agglomerates investigated by in situ FTIRS using CO as the probe molecule[J]. Journal of Physical Chemistry B, 2003, 107(36): 9808-9812.
[19] Wu C X, Lin H, Chen Y J, et al. Abnormal IR effects of Pt nanostructured surfaces upon CO chemisorption due to interaction and electron-hole damping[J]. Journal of Chemical Physics, 2004, 121(3): 1553-1556.
[20] Su Z F, Sun S G, Wu C X, et al. Study of anomalous infrared properties of nanomaterials through effective medium theory[J]. Journal of Chemical Physics, 2008, 129(4): 044707.
[21] Lambert D K. Vibrational Stark effect of adsorbates at electrochemical interfaces[J]. Electrochimica Acta, 1996, 41(5): 623-630.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.