Unveiling the role of defects in iron oxyhydroxide for oxygen evolution

Development of earth-abundant and robust oxygen evolution reaction (OER) catalysts is imperative for cost-effective hydrogen production via water electrolysis. Herein, we report ultrafine iron (oxy)hydroxide nanoparticles with average particle size of 2.6 nm and abundant surface defects homogeneously sup-ported on oleum-treated graphite (FeOx(n)@HG-T), providing abundant active sites for the OER. The opti-mal FeOx(0.03)@HG-110 exhibits high electrocatalytic OER activity and excellent stability. Electrochemical testing results and theoretical calculations reveal that the outstanding OER activity of FeOx(0.03)@HG-110 is due to its stronger charge transfer ability and lower OER energy barrier than defect-free FeOx nanoparticles. This work demonstrates that the OER performance of oxyhydroxide-based electrocatalysts can be improved by surface defect engineering.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study reports ultrafine iron (oxy)hydroxide nanoparticles supported on oleum-treated graphite, providing abundant active sites for the oxygen evolution reaction (OER). The optimal catalyst exhibits high electrocatalytic OER activity and excellent stability due to its stronger charge transfer ability and lower OER energy barrier. This work demonstrates the improvement of OER performance in oxyhydroxide-based electrocatalysts through surface defect engineering.