Characterization of hydrous manganite (γ-MnOOH) surfaces -: an XPS study

被引：50

作者：

Ramstedt, M ^{[1
]}

Shchukarev, AV ^{[1
]}

Sjöberg, S ^{[1
]}

机构：

[1] Umea Univ, Dept Chem, SE-90187 Umea, Sweden

来源：

SURFACE AND INTERFACE ANALYSIS | 2002年 / 34卷 / 01期

关键词：

XPS; manganite/water interface; pH dependence; dissolution; sample preparation;

D O I：

10.1002/sia.1376

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：

Crystalline manganite (gamma-MnOOH) has been synthesized and characterized using x-ray diffraction and high-resolution transmission electron microscopy techniques. The surface composition was studied with XPS between pH 0.4 and 11. Special pre-cooling procedures were developed to keep the manganite/water interface intact before and during XPS measurements. The O/OH group ratio differs between pH 6 and 11, in agreement with the acid/base characteristics of the surface. Below pH 6, on the other hand, drastic changes can be seen in the 0 1s spectra due to dissolution of manganite. Possibly the interaction of OH groups with HI in acidic suspensions is a first step leading to dissolution. The surface charge arising at high and low pH is compensated by the counter-ions Na+ and Cl-, respectively. The XPS spectra are presented and discussed in terms of the mechanisms for surface complexation and dissolution processes. Copyright (C) 2002 John Wiley Sons, Ltd.

引用

页码：632 / 636

页数：5

共 4 条

[1] Metal ion coordination at the water-manganite (γ-MnOOH) interface I.: An EXAFS study of cadmium(II) [J].