3D Core–Shell NiFeCr Catalyst on a Cu Nanoarray for Water Oxidation: Synergy between Structural and Electronic Modulation

Abstract

Low-cost transition metal-based electrocatalysts for water oxidation and understanding their structure−activity relationship are greatly desired for clean and sustainable chemical fuel production. Herein, a core− shell (CS) NiFeCr metal/metal hydroxide catalyst was fabricated on a 3D Cu nanoarray by a simple electrodeposition−activation method. A synergistic promotion effect between electronic structure modulation and nanostructure regulation was presented on a CS-NiFeCr oxygen evolution reaction (OER) catalyst: the 3D nanoarchitecture facilitates the mass transport process, the in situ formed interface metal/metal hydroxide heterojunction accelerates the electron transfer, and the electronic structure modulation by Cr incorporation improves the reaction kinetics. Benefiting from the synergy between structural and electronic modulation, the catalyst shows excellent activity toward water oxidation under alkaline conditions: overpotential of 200 mV at 10 mA/cm 2 current density and Tafel slope of 28 mV/dec. This work opens up a new window for understanding the structure−activity relationship of OER catalysts and encourages new strategies for development of more advanced OER catalysts.

NiFeCo oxide as an efficient and sustainable catalyst for the oxygen evolution reaction

“…The measured potential plateau of each electrode remained stable during each current step, which indicates high electrochemical stability. The potential increased with increasing current density without fluctuating, which suggesting the electrodes have outstanding mass and charge transport properties . The stability of an electrode significantly impacts the electrocatalytic process.…”

“…The potential increased with increasing current density without fluctuating, which suggesting the electrodes have outstanding mass and charge transport properties. 13 The stability of an electrode significantly impacts the electrocatalytic process. Long-term stability was obtained by performing chronoamperometry at 10 mA cm −2 .…”

“…Mixed metal alloys and layered double hydroxides (LDHs) have recently demonstrated outstanding electrochemical properties for the OER and HER . Other methodologies have also been employed to enhance the electrocatalytic performance of electrode materials, such as morphological engineering, hybrid composite synthesis, and doping .…”

“…Mixed metal alloys and layered double hydroxides (LDHs) have recently demonstrated outstanding electrochemical properties for the OER and HER. [11][12][13][14][15][16][17][18][19][20][21][22] Other methodologies have also been employed to enhance the electrocatalytic performance of electrode materials, such as morphological engineering, hybrid composite synthesis, and doping. [23][24][25] Binary oxides and there complex systems have been developed with metals that are abundant in the earth's crust for effective water catalytic activity.…”

Oxygen Isotope Labeling Experiments Reveal Different Reaction Sites for the Oxygen Evolution Reaction on Nickel and Nickel Iron Oxides

“…During this time,the Raman spectra were recorded after 1, 5, 10, and 20 mins.F or Ni and NiCo LDHs,t he peaks of d(Ni III À O), n(Ni III À O), and n(O À O) were immediately shifted back to the positions observed for the 16 O-labeled samples (Figure 3a,b). This result indicates that the 18 O-labeled lattice Oand NiOO À moieties in the Ni and NiCo LDH are readily exchanged by 16 Oatoms from 16 OH À during the OER. It follows that lattice oxygen in Ni and NiCo LDHs participates in the OER process,s imilar to some recently reported perovskite catalysts.…”