Excellent performance of nitrogen-doped carbon nanofibers as electrocatalysts for water splitting reactions

Green hydrogen production by water electrolysis with the least possible energy waste requires the application of suitable electrocatalytic electrodes. In this work, highly active, free-standing electrodes were prepared by deposition of nitrogen-doped carbon nanofibers (N-CNFs) on oxidized carbon cloth. Different types of N-CNFs with variable structures, nitrogen dopant concentrations and defect contents were synthesized. Their electrocatalytic activities as hybrids with oxidized and raw carbon cloth electrodes were evaluated in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). We show that the N-CNF sample with the highest nitrogen doping in the series (6.7 at.%) and the predominance of well-ordered herringbone/bamboo-like structure with abundant edge sites, exhibited both the highest OER and HER activities (with overpotentials of 330 and 410 mV, respectively at j = +/- 10 mA cm-2) and excellent performance stability. The hybrid material provided abundant active sites on N-CNFs that show good adhesion to the hydrophilic carbon cloth. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.