Aqueous-phase oxygen evolution reaction (OER) is the bottleneck of water splitting. The formation of the O−O bond involves the generation of paramagnetic oxygen molecules from the diamagnetic hydroxides. The spin configurations might play an important role in aqueous-phase molecular electrocatalysis. However, spintronic electrocatalysis is almost an uncultivated land for the exploration of the oxygen molecular catalysis process. Herein, we present a novel magnetic Fe III site spin-splitting strategy, wherein the electronic structure and spin states of the Fe III sites are effectively induced and optimized by the Jahn−Teller effect of Cu 2+ . The theoretical calculations and operando attenuated total reflectance-infrared Fourier transform infrared (ATR FT-IR) reveal the facilitation for the O−O bond formation, which accelerates the production of O 2 from OH − and improves the OER activity. The Cu 1 −Ni 6 Fe 2 −LDH catalyst exhibits a low overpotential of 210 mV at 10 mA cm −2 and a low Tafel slope (33.7 mV dec −1 ), better than those of the initial Cu 0 −Ni 6 Fe 2 −LDHs (278 mV, 101.6 mV dec −1 ). With the Cu 2+ regulation, we have realized the transformation of NiFe−LDHs from ferrimagnets to ferromagnets and showcase that the OER performance of Cu−NiFe−LDHs significantly increases compared with that of NiFe−LDHs under the effect of a magnetic field for the first time. The magnetic-fieldassisted Cu 1 −Ni 6 Fe 2 −LDHs provide an ultralow overpotential of 180 mV at 10 mA cm −2 , which is currently one of the best OER performances. The combination of the magnetic field and spin configuration provides new principles for the development of highperformance catalysts and understandings of the catalytic mechanism from the spintronic level.
Highly
efficient and low-cost oxygen reduction reaction electrocatalysts
play key roles in the development of advanced energy conversion and
storage devices, such as fuel cells and metal–air batteries.
Herein, a facile strategy of synthesizing cobalt single atoms anchored
on an ultrathin N-doped carbon nanosheet electrocatalyst (marked as
CoSAs/N-CNS) via an in situ g-C3N4 template strategy was reported. Impressively, benefiting
from highly active Co–Nx sites and highly porous and ultrathin
nanosheet morphology which has rich edges and more three-phase boundaries,
the as-synthesized CoSAs/N-CNS exhibits markedly enhanced ORR activities
under alkaline conditions with half-wave potential (E
1/2) as high as 0.91 V vs RHE, as well as durability of
∼67 h. Furthermore, compared with Pt/C, the CoSAs/N-CNS-based
Zn–air battery presents outstanding discharge–charge
performance, larger power density of 157.7 mW cm–2, and robust durability with a slight decay after 150 h (900 cycles).
The experimental and theoretical results fully show the advantages
of CoSAs/N-CNS, which also provides a new insight for the design and
development of high-performance atomically dispersed metal active
site electrocatalysts toward ORR.
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