Pyrolyzed cobalt porphyrin-modified carbon nanomaterial as an active catalyst for electrocatalytic water oxidation

•Noble-metal-free cobalt porphyrin-based catalyst for water oxidation.•Carbon support improves catalytic current density.•Heat-treatment enhances the catalytic activity.•High Faradaic efficiency and turnover frequency.

Design and preparation of highly active catalysts for the oxygen evolution reaction (OER) is important to achieve efficient water splitting. Herein, we report on the use of pyrolyzed cobalt porphyrin/carbon materials as noble-metal-free electrocatalysts for the catalytic OER. The cobalt porphyrin/carbon electrocatalysts were prepared by loading a cobalt porphyrin complex on a carbon support, followed by heat treatment under argon atmosphere. Cyclic voltammetry showed that the maximum catalytic activity was obtained after heat treatment at 1000 °C. The turnover frequency was ∼0.078 s−1 based on cobalt under an applied anodic potential of 1.31 V (vs NHE) at pH = 9.2. The catalyst was further characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). These results indicate that the pyrolyzed cobalt porphyrin/carbon nanomaterial is a promising catalyst for OER.

Graphical abstractPyrolyzed cobalt porphyrin/carbon materials as noble-metal-free electrocatalysts for the catalytic OER with high performance.Figure optionsDownload full-size imageDownload as PowerPoint slide