高等学校化学学报 ›› 2000, Vol. 21 ›› Issue (S1): 377.

• Chemistry in Surface Science • 上一篇    下一篇

Scanning Tunnelling Microscopy Study of Chloride Adsorbed on Cu(110) Surfaces in Hydrochloric Acid Solution

LI W.H.1, WANG Yi1,2, YE J.H.1, LI S.F.Y.2   

  1. 1. Institute of Materials Research and Engineering, 3 Research Link 3, Singapore 117602, Republic of Singapore;
    2. Department of Chemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Republic, of Singapore
  • 出版日期:2000-12-31 发布日期:2000-12-31
  • 通讯作者: YE J.H. E-mail:jh-ye@imre.org.sg

Scanning Tunnelling Microscopy Study of Chloride Adsorbed on Cu(110) Surfaces in Hydrochloric Acid Solution

LI W.H.1, WANG Yi1,2, YE J.H.1, LI S.F.Y.2   

  1. 1. Institute of Materials Research and Engineering, 3 Research Link 3, Singapore 117602, Republic of Singapore;
    2. Department of Chemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Republic, of Singapore
  • Online:2000-12-31 Published:2000-12-31
  • Contact: YE J.H. E-mail:jh-ye@imre.org.sg

摘要:

Fundamental studies of the interaction of chloride with copper is of great interest from both scientific and technological view points since it is related to the copper electroplating and also the halogen etching processes[1]. In this paper, in-situ scanning tunneling microscopy (STM) has been employed to study chloride adsorption on Cu(110) electrode in hydrochloride acid aqueous solution. The atomic resolution images of chloride adsorbed on Cu(111) surface have been obtained over the potential range from -400 mV to -100 mV (vs. SCE). A (l×l) structure for Cu(110) substrate was observed at the potential negative than -450 mV in which the chloride anions are desorbed. Our results indicate that the chloride anions are very strongly adsorbed on the Cu(110) surface at the potential positive than -400 mV. The images taken over a large region show parallel rows on the terraces and monolayer straight steps, which run along the[001] direction of the substrate lattice. The parallel row structures observed here are suggested to attribute from the chloride adlayers. The different corrugation height and periodical modulation in the height along[110] direction observed indicates that chloride anions are located at physically non-equivalent binding sites. Models are proposed to interpret the structures with three-fold periodicity and four-fold periodicity along[110] direction with a (4×1) structure containing three chloride anions and a (5×1) structure containing four chloride anions, respectively.

Abstract:

Fundamental studies of the interaction of chloride with copper is of great interest from both scientific and technological view points since it is related to the copper electroplating and also the halogen etching processes[1]. In this paper, in-situ scanning tunneling microscopy (STM) has been employed to study chloride adsorption on Cu(110) electrode in hydrochloride acid aqueous solution. The atomic resolution images of chloride adsorbed on Cu(111) surface have been obtained over the potential range from -400 mV to -100 mV (vs. SCE). A (l×l) structure for Cu(110) substrate was observed at the potential negative than -450 mV in which the chloride anions are desorbed. Our results indicate that the chloride anions are very strongly adsorbed on the Cu(110) surface at the potential positive than -400 mV. The images taken over a large region show parallel rows on the terraces and monolayer straight steps, which run along the[001] direction of the substrate lattice. The parallel row structures observed here are suggested to attribute from the chloride adlayers. The different corrugation height and periodical modulation in the height along[110] direction observed indicates that chloride anions are located at physically non-equivalent binding sites. Models are proposed to interpret the structures with three-fold periodicity and four-fold periodicity along[110] direction with a (4×1) structure containing three chloride anions and a (5×1) structure containing four chloride anions, respectively.

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