Advanced Functional Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 23, 2024
Abstract
Inhibiting
the
deactivation
of
nickel‐based
catalysts
caused
by
self‐oxidation
and
competitive
adsorption
behavior
is
still
a
major
challenge
for
urea
oxidation
reaction
(UOR),
especially
under
industrial‐level
current
densities.
In
this
study,
crystalline
NiSe
2
/amorphous
NiFe‐LDH
(NiSe
/NiFe‐LDH)
heterojunction
catalyst
rationally
constructed
selective
electrocatalytic
UOR.
situ
Raman
spectra
ex
characterization
results
reveal
that
such
structure
can
tailor
impede
accumulation
NiOOH
species
during
UOR
process.
Density
function
theory
simulations
disclose
self‐driven
charge
transport
from
electron‐deficient
region
to
electron‐rich
would
induce
formation
local
electrophilic/nucleophilic
adsorb
electron‐donating
‐NH
electron‐withdrawing
C
=
O
groups,
respectively.
This
optimizes
molecules
hinders
overaccumulation
OH
−
ions
on
surface
/NiFe‐LDH,
which
beneficial
priority
occurrence
over
oxygen
evolution
(OER)
realization
high
selectivity.
Benefiting
tailored
favorable
adsorption,
/NiFe‐LDH
could
act
as
high‐selective
anode
achieve
ultrahigh
800
mAcm
−2
only
at
1.447
V.
Besides,
UV–vis
spectrophotometry
also
unveiled
has
capability
electrochemically
degrade
urea,
offering
great
promise
practical
application
potentials.
Two-dimensional
(2D)
conjugated
metal-organic
frameworks
(c-MOFs)
have
attracted
extensive
interest
in
electrochemical
fields
due
to
their
inherent
electrical
conductivity.
However,
the
severe
interlayer
stacking
still
poses
barriers
toward
potential
applications.
The
reliable
synthesis
of
ultrathin
c-MOF
nanosheets
is
crucial
yet
remains
challenging.
Herein,
we
demonstrate
an
exfoliation
approach
obtain
from
layer-stacked
crystals.
Our
results
reveal
electric
field-induced
ion
intercalation
mechanism
and
provide
a
viable
method
for
M-HHTP
(M
=
Ni,
Cu,
Co;
HHTP
2,3,6,7,10,11-hexahydroxytriphenylene)
nanosheets.
To
prove
utility,
obtained
Ni-HHTP
as
urea
oxidation
reaction
(UOR)
catalysts
achieve
ultrahigh
current
density
165.7
mA
cm-2
at
1.35
V
versus
reversible
hydrogen
electrode
nearly
100%
selectivity
N-products.
Experimental
characterization
theoretical
calculations
that
fully
exposed
square
planar
NiO4
active
centers
effectively
reduce
energy
barrier
C-N
bond
cleavage
UOR
suppress
parasitic
oxygen
evolution
reaction.
Abstract
To
generate
hydrogen
sustainably,
it
is
crucial
to
substitute
the
kinetically
slower
oxygen
evolution
reaction
(OER)
with
urea
oxidation
(UOR)
at
anode.
This
necessitates
designing
of
highly
active
and
stable
Co‐based
electrocatalysts
for
UOR.
Herein,
influence
electronic
modulation
in
synthesized
borophene–cobalt
phosphate
catalyst
(B@CP)
generating
sites
UOR
was
studied.
The
addition
alkaline
electrolyte
as
a
sacrificial
agent
significantly
reduced
potential
required
by
B@CP
compared
OER
attaining
fixed
current
density.
achieved
densities
10
mA
cm
−2
100
potentials
1.31
V
1.40
V,
respectively.
Adding
borophene
also
modified
its
morphology
charge
transport,
enhancing
kinetics,
reducing
transfer
resistance,
exposing
more
electrochemically
sites.
Moreover,
displayed
long‐term
stability
50
h.
work
will
encourage
development
innovative
strategies
tuning
properties
different
transition
metal‐based
via
various
energy
conversion
applications.
Advanced Functional Materials,
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 23, 2024
Abstract
Inhibiting
the
deactivation
of
nickel‐based
catalysts
caused
by
self‐oxidation
and
competitive
adsorption
behavior
is
still
a
major
challenge
for
urea
oxidation
reaction
(UOR),
especially
under
industrial‐level
current
densities.
In
this
study,
crystalline
NiSe
2
/amorphous
NiFe‐LDH
(NiSe
/NiFe‐LDH)
heterojunction
catalyst
rationally
constructed
selective
electrocatalytic
UOR.
situ
Raman
spectra
ex
characterization
results
reveal
that
such
structure
can
tailor
impede
accumulation
NiOOH
species
during
UOR
process.
Density
function
theory
simulations
disclose
self‐driven
charge
transport
from
electron‐deficient
region
to
electron‐rich
would
induce
formation
local
electrophilic/nucleophilic
adsorb
electron‐donating
‐NH
electron‐withdrawing
C
=
O
groups,
respectively.
This
optimizes
molecules
hinders
overaccumulation
OH
−
ions
on
surface
/NiFe‐LDH,
which
beneficial
priority
occurrence
over
oxygen
evolution
(OER)
realization
high
selectivity.
Benefiting
tailored
favorable
adsorption,
/NiFe‐LDH
could
act
as
high‐selective
anode
achieve
ultrahigh
800
mAcm
−2
only
at
1.447
V.
Besides,
UV–vis
spectrophotometry
also
unveiled
has
capability
electrochemically
degrade
urea,
offering
great
promise
practical
application
potentials.
