Unraveling oxygen evolution reaction on carbon-based electrocatalysts: effect of oxygen doping on adsorption of oxygenated intermediates

Published: January 5, 2017Carbon-based nanomaterials have been widely studied as promising electrocatalysts for energy conversion and storage. Understanding the oxygen evolution and reduction reactions on carbon-based nanomaterials is of critical importance for development of highly active metal-free electrocatalysts. Here, the adsorption of oxygenated intermediates during oxygen evolution reaction (OER) on carbon nanotubes (CNTs) was examined by ex-situ X-ray photoelectron spectroscopy and in situ electrochemical impedance spectroscopy. The results demonstrate that the carbon atoms on CNTs near the C═O functional groups are active for OER. On the basis of this result, we further revealed the origin of the enhanced intermediate adsorption on surface-oxidized CNTs and the relationship between surface groups and apparent activation energy. Our study gained new understanding of OER on oxygen-doped carbon nanomaterials and provided an effective approach for investigating electrocatalysis on heteroatom-doped carbon electrocatalysts.Laiquan Li, Hongbin Yang, Jianwei Miao, Liping Zhang, Hsin-Yi Wang, Zhiping Zeng, Wei Huang, Xiaochen Dong, and Bin Li