EVIDENCE FOR AN AG4O3 PHASE OF SILVER-OXIDE

被引：37

作者：

MANSOUR, AN

机构：

[1] Research and Technology Department, Naval Surface Warfare Center, Silver Spring, MD 20903-5000

[2] Naval Surface Warfare Center, Code R34, Bldg. 30, Silver Spring, MD 20903-5000

来源：

JOURNAL OF PHYSICAL CHEMISTRY | 1990年 / 94卷 / 02期

关键词：

D O I：

10.1021/j100365a093

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The structure of chemically and electrochemically prepared AgO materials was investigated by extended X-ray absorption fine structure (EXAFS) spectroscopy. It was found that chemically prepared (CP) AgO is composed of Ag+ and Ag3+ ions coordinated with two oxygens at 2.13 Å and four oxygens at 1.99 Å, respectively. For electrochemically prepared (EP) AgO, the Ag+ ions are also coordinated with two oxygens at a distance of 2.13 Å. However, the coordination number for the Ag3+ ions varies from 2.8 to 3.5 oxygens without any significant change in the coordination distance of 1.99 Å. That is, EP AgO is really AgO1-δ, where δ is the degree of oxygen deficiency near the Ag3+ ions. The magnitude of δ can be as large as 0.29 ± 0.05 and is a strong function of preparation procedures. The EXAFS results reveal that a phase of silver oxide, Ag4O3, is formed electrochemically. The EXAFS results also suggest that the electrochemical oxidation of Ag or Ag2O to AgO proceeds via the formation of Ag4O3 as an intermediate step.

引用

页码：1006 / 1010

页数：5

共 29 条

[1] TRANSFERABILITY OF PHASE-SHIFTS IN EXTENDED X-RAY ABSORPTION FINE-STRUCTURE [J].