Anisotropic etching of rhodium and gold as the onset of nanoparticle formation by cathodic corrosion

Author:

Hersbach Thomas J. P.1234ORCID,Mints Vladislav A.1234,Calle-Vallejo Federico1234,Yanson Alexei I.564,Koper Marc T. M.1234

Affiliation:

1. Leiden Institute of Chemistry

2. Leiden University

3. 2300 RA Leiden

4. The Netherlands

5. Cosine Measurement Systems

6. 2361 HE Warmond

Abstract

Cathodic corrosion is a phenomenon in which negatively polarized metal electrodes are degraded by cathodic etching and nanoparticle formation. Though these changes are dramatic and sometimes even visible by eye, the exact mechanisms underlying cathodic corrosion are still unclear. This work aims to improve the understanding of cathodic corrosion by studying its onset on rhodium and gold electrodes, which are subjected to various constant cathodic potentials in 10 M NaOH. After this polarization, the electrodes are studied using cyclic voltammetry and scanning electron microscopy, allowing a corrosion onset potential of −1.3 Vvs.NHE for rhodium and −1.6 Vvs.NHE for gold to be defined. The mildness of the potentials on both metals suggests that cathodic corrosion is less extreme and more ubiquitous than expected. Furthermore, we are able to observe well-defined rectangular etch pits on rhodium. Combined with rhodium cyclic voltammetry, this indicates a strong preference for forming (100) sites during corrosion. In contrast, a (111) preference is indicated on gold by voltammetry and the presence of well-oriented quasi-octahedral nanoparticles. This different etching behavior is suggested to be caused by preferential adsorption of sodium ions to surface defects, as is confirmed by density functional theory calculations.

Funder

Nederlandse Organisatie voor Wetenschappelijk Onderzoek

Publisher

Royal Society of Chemistry (RSC)

Subject

Physical and Theoretical Chemistry

Reference32 articles.

1. P. Vanýsek , CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, FL, 96th edn, 2015, ch. 5, pp. 5-80–5-89

2. Identifying active surface phases for metal oxide electrocatalysts: a study of manganese oxide bi-functional catalysts for oxygen reduction and water oxidation catalysis

3. Pt(111) surface disorder kinetics in perchloric acid solutions and the influence of specific anion adsorption

4. Dissolution of Noble Metals during Oxygen Evolution in Acidic Media

5. M. Pourbaix , Atlas of electrochemical equilibria in aqueous solutions, National Association of Corrosion Engineers, 2nd edn, 1974, p. 644

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3