Scientists from the Institute of Solid State Physics, Hefei Institutes of Physical Science developed an efficient transition metal electrocatalyst for improvement of oxygen evolution reaction. The research was published in Small.
The development of alternative clean energy sources is an urgent quest due to the rapid depletion of fossil fuels. Electrochemical water splitting is one of the most promising technologies toward developing sustainable energy storage and conversion systems.
Unfortunately, the full water splitting reaction is restricted by the oxygen evolution reaction (OER) process, mainly owing to the slow kinetic process of the oxygen related reactions.
Co-based layered double hydroxides (LDHs) display a considerable OER activity and high binding energy of oxygen intermediates on the Co active sites as the 3d band center increases from late transition metals to early ones in the periodic table.
The binding energies of the four oxygen intermediates follows a linear relation which yields a theoretical limit of the overpotential ~0.35 V. How to propose effective strategies to break the theoretical limitation becomes significant but challenging.
Herein, the team reported a unique Cr doped CoFe layered double hydroxides nanorod arrays supported on a nickel foam (Cr-CoFe LDHs/NF) electrode by a one-step hydrothermal strategy.
After the Cr doping, the Cr-CoFe LDHs/NF catalyst demonstrated a superior durability and high activity for oxygen evolution reaction. Density functional theory (DFT) calculations unveiled that Cr dopants as new active sites could improve the electron-donation ability of the resultant Cr-CoFe LDHs.
The present results might provide insights into developing highly active OER catalysts for electrochemical water splitting.
This research was supported by National Science Fund for Distinguished Young Scholars, Natural Science Foundation of China, the Major Program of Development Foundation of Hefei Center for Physical Science and Technology.
Figure 1. (a) Schematic preparation of Cr-CoFe LDHs/NF. (b) OER performance of Cr-CoFe LDHs/NF in 1M KOH. (c) The charge density difference plots for OOH (upper panel) and OH (lower panel) on CoFe LDHs and Cr-CoFe LDHs with an isosurface value of 0.005 e•Å-3. £¨Image by WEN Lulu£©
Link to the paper: https://onlinelibrary.wiley.com/doi/full/10.1002/smll.201902373