碲在金衬底上的不可逆吸附行为及其欠电位沉积机制的研究

研究了碲在金衬底上的不可逆吸附行为特征及其对碲原子欠电位沉积行为的影响. 同时也探讨了碲原子于金衬底上的欠电位沉积机制. 结果显示在开路条件下碲原子在金衬底表面具有不可逆的吸附行为, 证实了在金的双电层范围内很难将这种碲的吸附物移走. 为了完全移走碲的吸附物, 需要采用特定的电化学清洗程序. 发现碲的吸附物移走发生在电位循环至金的氧化区域, 且在该区域这种碲的吸附物移走与金的表面氧化同时发生. 扫描速率分析结果证实碲欠电位沉积在金表面符合Sanchez-Maestre模型的三个标准, 说明碲原子于金衬底上欠电位沉积符合二维形核和生长机制.

Electrochemical Behavior of Irreversibly Adsorbed Te Monolayer on Au Substrate and the Mechanism of Te Underpotential Deposition

Electrochemical characterization of irreversibly adsorbed tellurium monolayers on Au substrate and examination of the effect of tellurium adsorbates on the underpotential deposition of tellurium on Au substrate have been performed in this paper.The mechanism of Te underpotential deposition has also been studied.The results show that the tellurium adsorbates could be irreversibly adsorbed upon the Au substrate surface under the open-circuit conditions.Subsequent removal of the Te adsorbates was also proved to be very difficult within the Au double-layer region,and a standard electrochemical cleaning procedure was necessary to remove the Te adsorbates completely.When the potential was cycled into the Au oxidation re-gion,a substantial loss of Te adsobates was observed,which occurred simultaneously with the Au oxidation features.The scan rate analysis of Te underpotential deposition on Au was fulfilled,which agreed well with the model developed by Sanchez-Maestre,and verified that Te underpotential deposition onto Au could proceed by a two-dimensional nucleation and growth mechanism.