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.
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