Electrocatalytic oxygen evolution at surface-oxidized multiwall carbon nanotubes

Xunyu Lu, Wai Leung Yim, Bryan H R Suryanto, Chuan Zhao

Research output: Contribution to journalArticleResearchpeer-review

336 Citations (Scopus)

Abstract

Large-scale storage of renewable energy in the form of hydrogen (H2) fuel via electrolytic water splitting requires the development of water oxidation catalysts that are efficient and abundant. Carbon-based nanomaterials such as carbon nanotubes have attracted significant applications for use as substrates for anchoring metal-based nanoparticles. We show that, upon mild surface oxidation, hydrothermal annealing and electrochemical activation, multiwall carbon nanotubes (MWCNTs) themselves are effective water oxidation catalysts, which can initiate the oxygen evolution reaction (OER) at overpotentials of 0.3 V in alkaline media. Oxygen-containing functional groups such as ketonic C=O generated on the outer wall of MWCNTs are found to play crucial roles in catalyzing OER by altering the electronic structures of the adjacent carbon atoms and facilitates the adsorption of OER intermediates. The well-preserved microscopic structures and highly conductive inner walls of MWCNTs enable efficient transport of the electrons generated during OER.

Original languageEnglish
Pages (from-to)2901-2907
Number of pages7
JournalJournal of the American Chemical Society
Volume137
Issue number8
DOIs
Publication statusPublished - 4 Mar 2015
Externally publishedYes

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