钴铂合金薄膜的循环伏安电沉积及其异常红外性能研究

Electrochemical Deposition of CoPt Alloy Thin Film and Its Abnormal Infrared Effects

运用循环伏安电沉积在玻碳基底上制得纳米结构钴铂合金薄膜,扫描电子显微镜和X-射线能量散射谱研究表明,钴铂薄膜主要由平均粒经为139 nm的纳米粒子组成,钴和铂的原子比为3∶5.以CO为探针分子,电化学原位FTIR反射光谱研究发现钴铂薄膜具有异常红外效应.吸附态CO发生异常红外吸收,谱峰比本体钴和铂分别增强了34和43倍.

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 abnor mal 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 impor- tance 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.