Inorganic Chemistry,
Год журнала:
2023,
Номер
62(38), С. 15766 - 15776
Опубликована: Сен. 13, 2023
Large-scale
solar-driven
water
splitting
is
a
way
to
store
energy,
but
it
requires
the
development
of
practical
and
durable
oxygen
evolution
reaction
(OER)
catalysts.
The
present
paper
aims
investigate
mechanism
OER,
local
pH,
high-valent
metal
ions,
limitations,
conversions,
details
during
OER
in
presence
FeNi
foam
using
situ
surface-enhanced
Raman
spectroscopy.
This
research
also
explores
use
spectroscopy
for
detecting
species
on
surfaces
OER.
acidic
media
around
electrode
not
only
limit
process
affect
phosphate
ion
protonation
overall
catalysis
effectiveness.
study
proposes
that
hydroxides
serve
as
true
catalysts
under
neutral
conditions,
rather
than
phosphates.
However,
remain
crucial
proton
transfer
molecule
adsorption.
Changes
observed
pH
at
open-circuit
potential
suggest
new
insights
concerning
coordination
Ni(II)
ions
certain
conditions.
By
extrapolating
Tafel
plot,
overpotential
onset
was
determined
be
470
mV.
Furthermore,
overpotentials
current
densities
1
5
mA/cm2
were
590
790
mV,
respectively.
These
findings
offer
valuable
into
advancement
our
understanding
underlying
efficient
splitting;
both
are
elements
purpose
energy
storage.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(47)
Опубликована: Авг. 23, 2024
Abstract
Although
the
electronic
state
of
catalysts
is
strongly
corrected
with
their
oxygen
evolution
reaction
(OER)
performances,
understanding
role
spin
in
dynamic
structure
during
OER
process
still
challenging.
Herein,
we
developed
a
regulation
strategy
to
boost
performance
CoOOH
through
elemental
doping
(CoMOOH,
M=V,
Cr,
Mn,
Co
and
Cu).
Experimental
results
including
magnetic
characterization,
situ
X‐ray
absorption
spectroscopy,
Raman
density
functional
theory
calculations
unveil
that
Mn
could
successfully
increase
sites
from
low
intermediate
state,
leading
largest
lattice
distortion
smallest
energy
gap
between
d
xy
z
2
orbitals
among
obtained
CoMOOH
electrocatalysts.
Benefiting
promoted
electron
transfer
orbital,
facilitated
formation
active
high‐valent
*O−Co
(IV)
species
at
applied
potential,
reduced
barrier
rate‐determining
step,
CoMnOOH
exhibits
highest
performance.
Our
work
provides
significant
insight
into
correction
by
metal
oxyhydroxides,
paving
new
avenue
for
rational
design
high‐activity
Abstract
Developing
high‐performance
oxygen
evolution
reaction
(OER)
electrocatalysts
that
can
operate
stably
at
large
current
densities
in
seawater
plays
a
crucial
role
enabling
large‐scale
hydrogen
production,
however,
it
remains
significant
challenge.
Herein,
sulfur‐doped
NiFe
layered
double
hydroxide
nanosheet
(S‐NiFe
LDH)
grown
on
3D
porous
nickel
foam
skeleton
is
synthesized
through
electrochemical
deposition
and
ion‐exchange
strategies
room
temperature
as
high‐performance,
highly
selective,
durable
OER
electrocatalyst
for
electrolysis
density.
The
incorporation
of
S
enhance
the
conductivity,
promote
structural
reconstruction
to
form
active
oxyhydroxides,
well
improve
anti‐corrosion
ability
chloride
ions.
Furthermore,
due
its
unique
self‐supporting
structure
superhydrophilicity,
which
provide
abundant
sites
efficient
bubble
release,
optimized
demands
minimal
overpotential
278
299
mV
generate
1000
mA
cm
−2
alkaline
freshwater/seawater,
respectively,
confirming
excellent
activity.
Meanwhile,
also
demonstrates
exceptional
stability
both
media,
maintains
stable
performance
duration
200
h
500
.
present
work
offers
an
strategy
innovative
viewpoint
developing
electrolysis.
Electrolyte
modulation
can
enhance
the
performance
of
electrocatalysts
for
oxygen
evolution
reaction
(OER)
by
tailoring
electrocatalyst-electrolyte
interface,
but
role
anion
additives
remains
controversial.
Herein,
we
report
our
findings
on
unraveling
effects
oxyanions
(NO3–,
SO42–,
and
PO43–)
identifying
Fe
impurities
as
key
factor
driving
OER
activity
enhancement
in
Ni
hydr(oxy)oxide
model
catalysts.
impurities,
introduced
via
oxyanion
salts,
significantly
activity,
while
themselves
have
minimal
direct
impact
when
ions
are
removed.
Our
results,
including
operando
Raman
spectroscopy,
reveal
that
enhances
reducibility/redox
reversibility.
X-ray
absorption
spectroscopy
density
functional
theory
calculations
indicate
preferentially
adsorbs
surface
sites
with
higher
deprotonation
energy.
These
critical
surface-adsorbed
modulating
highlight
overlooked
impurity
electrocatalysis
studying
additive
electrolyte
modulation.
Inorganic Chemistry Frontiers,
Год журнала:
2023,
Номер
11(2), С. 498 - 507
Опубликована: Ноя. 21, 2023
Continuous
leaching
of
MoO
4
2−
accelerates
the
collapse
host
structure
and
generation
NiFeOOH.
The
re-adsorbed
modify
electronic
environment
Ni
Fe
sites
modulates
their
d-band
centers,
boosting
OER
kinetics.
ACS Catalysis,
Год журнала:
2024,
Номер
14(14), С. 10871 - 10881
Опубликована: Июль 4, 2024
Sluggish
mass
transfer
of
OH–
in
alkaline
oxygen
evolution
reaction
(OER),
resulting
from
densely
packed
hydrated
layers
at
the
outer
Helmholtz
plane
(OHP),
becomes
one
main
bottlenecks
to
improve
overall
efficiency
electrochemical
devices.
Herein,
we
report
a
hydration-layer-destabilizing
route
by
binding
formate
oxyanions
onto
catalyst
surface
form
transport
pathways,
favorable
for
fast
and
significantly
improving
OER
activity.
The
experiments
indicate
that
formate-modified
NiCo
hydroxide
(NiCo–HCOO–)
shows
increased
kinetics,
smaller
overpotential,
higher
turnover
frequency
(TOF)
than
without
modification.
theoretical
calculations
reveal
formate-induced
hydrogen-bonding
interaction
with
water
molecules
could
destabilize
potassium
ion
OHP,
lowering
resistance
paving
pathway
transfer.
assembled
flow
electrolyzer
NiCo–HCOO–
anode
operate
400
mA
cm–2
only
2.1
V
over
300
h.
This
study
provides
an
efficient
strategy
designing
high-activity
electrocatalysts
toward
advanced
energy
conversion
