Abstract
Exploring cost-effective and efficient bifunctional electrocatalysts via simple fabrication strategies is strongly desired for practical water splitting. Herein, an easy and fast one-step electrodeposition process is developed to fabricate W-doped NiFe (NiFeW)-layered double hydroxides with ultrathin nanosheet features at room temperature and ambient pressure as bifunctional catalysts for water splitting. Notably, the NiFeW nanosheets require overpotentials of only 239 and 115 mV for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, to reach a current density of 10 mA/cm2 in alkaline media. Their exceptional performance is further demonstrated in a full electrolyzer configuration with the NiFeW as both anode and cathode catalysts, which achieves a low cell voltage of 1.59 V at 10 mA/cm2, 110 mV lower than that of the commercial IrO2 (anode) and Pt (cathode) catalysts. Moreover, the NiFeW nanosheets are superior to various recently reported bifunctional electrocatalysts. Such remarkable performances mainly ascribe to W doping, which not only effectively modulates the electrocatalyst morphology but also engineers the electronic structure of NiFe hydroxides to boost charge-transfer kinetics for both the OER and HER. Hence, the ultrathin NiFeW nanosheets with an efficient fabrication strategy are promising as bifunctional electrodes for alkaline water electrolyzers.
Original language | English |
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Pages (from-to) | 20070-20080 |
Number of pages | 11 |
Journal | ACS Applied Materials and Interfaces |
Volume | 13 |
Issue number | 17 |
DOIs | |
State | Published - May 5 2021 |
Funding
The authors greatly appreciate the support from the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Fuel Cell Technologies Office Award no. DE-EE0008426 and DE-EE0008423, and National Energy Technology Laboratory under Award DE-FE0011585. A portion of the research was performed as part of a user project through the Center for Nanophase Materials Sciences, which is a U.S. DOE Office of Science User Facility. The authors also wish to express their appreciation to Alexander Terekhov, Douglas Warnberg, and Dr. Brian Canfield for their help.
Keywords
- bifunctional electrocatalysts
- electrodeposition
- engineered electronic structure
- ultrathin W-doped NiFe nanosheets
- water splitting