1. Unveiling the role of defects in iron oxyhydroxide for oxygen evolution.
- Author
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Han, Jingyi, Niu, Xiaodi, and Guan, Jingqi
- Subjects
- *
IRON , *HYDROGEN evolution reactions , *ACTIVATION energy , *WATER electrolysis , *SURFACE defects , *OXYGEN evolution reactions , *OXYGEN , *CHARGE transfer - Abstract
Compared with defect-free FeO x , the ultrafine FeO x in the FeO x (0.03)@HG-110 with abundant surface defects shows lower energy barrier and higher OER activity. [Display omitted] • The FeO x (0.03)@HG-110 exhibits an OER overpotential as low as 342 mV at 10 mA cm−2. • The average particle size of FeOx is ca. 1.6 nm. • FeO x (0.03)@HG-110 possesses a low E a of 35.9 kJ mol−1. • The rate-determining step is *O → *OOH with the energy barriers of 0.79 eV. 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 supported on oleum-treated graphite (FeO x (n)@HG-T), providing abundant active sites for the OER. The optimal FeO x (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 FeO x (0.03)@HG-110 is due to its stronger charge transfer ability and lower OER energy barrier than defect-free FeO x nanoparticles. This work demonstrates that the OER performance of oxyhydroxide-based electrocatalysts can be improved by surface defect engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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