Ball-milled sulfur-doped graphene materials contain metallic impurities originating from ball-milling apparatus: their influence on the catalytic properties. Issue 27 (17th June 2016)

• Record Type: Journal Article
• Authors: Chua, Chun Kiang; Sofer, Zdeněk; Khezri, Bahareh; Webster, Richard D.; Pumera, Martin
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 27(2016)
• Page Start: 17875
• Page End: 17880
• Publication Date: 2016-06-17
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp03004a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Ball-milling apparatus is a source of metallic impurities in graphene materials. Sulfur-doped graphene obtained from zirconium dioxide-based ball-milling apparatus contains drastically lower amount of metallic impurities than that obtained from stainless-steel based ball-milling apparatus. The metallic impurities exhibit catalytic effects toward the electrochemical catalysis of hydrazine and cumene hydroperoxide. Abstract : Graphene materials have found applications in a wide range of devices over the past decade. In order to meet the demand for graphene materials, various synthesis methods are constantly being improved or invented. Ball-milling of graphite to obtain graphene materials is one of the many versatile methods to easily obtain bulk quantities. In this work, we show that the graphene materials produced by ball-milling are spontaneously contaminated with metallic impurities originating from the grinding bowls and balls. Ball-milled sulfur-doped graphene materials obtained from two types of ball-milling apparatus, specifically made up of stainless steel and zirconium dioxide, were investigated. Zirconium dioxide-based ball-milled sulfur-doped graphene materials contain a drastically lower amount of metallic impurities than stainless steel-based ball-milled sulfur-doped graphene materials. The presence of metallic impurities is demonstrated by their catalytic effects toward the electrochemical catalysis of hydrazine and cumene hydroperoxide. The general impression toward ball-milling of graphite as a versatile method for the bulk production of 'metal-free' graphene materials without the need for post-processing and the selection of ball-milling tools should be cautioned. These findings would have wide-reaching implications for graphene research.