Small,
Journal Year:
2023,
Volume and Issue:
20(6)
Published: Oct. 5, 2023
Abstract
It
is
challenging
yet
promising
to
design
highly
accessible
N‐doped
carbon
skeletons
fully
expose
the
active
sites
inside
single‐atom
catalysts.
Herein,
mesoporous
hollow
spheres
with
regulatable
through‐pore
size
can
be
formulated
by
a
simple
sequential
synthesis
procedure,
in
which
condensed
SiO
2
acted
as
removable
dual‐templates
produce
both
interiors
and
through‐pores,
meanwhile,
co‐condensed
polydopamine
shell
served
precursor.
After
that,
Fe─N─C
(HSs)
obtained
after
rationally
implanting
Fe
single‐atoms.
Microstructural
analysis
X‐ray
absorption
fine
structure
reveal
that
high‐density
Fe─N
4
together
tiny
clusters
are
uniformly
distributed
on
skeleton
abundant
through‐pores.
Benefitted
from
arising
unique
architecture,
HSs
demonstrate
excellent
oxygen
reduction
reaction
(ORR)
performance
alkaline
media
half‐wave
potential
up
0.90
V
versus
RHE
remarkable
stability,
exceeding
commercial
Pt/C.
When
employing
air‐cathode
catalysts,
assembled
Zn–air
batteries
deliver
high
peak
power
density
of
204
mW
cm
−2
stable
discharging
voltage
plateau
over
140
h.
Small,
Journal Year:
2023,
Volume and Issue:
19(21)
Published: Feb. 26, 2023
Single-atom
Fe-N-C
(Fe1
-N-C)
materials
represent
the
benchmarked
electrocatalysts
for
oxygen
reduction
reaction
(ORR).
However,
single
Fe
atoms
in
carbon
skeletons
cannot
be
fully
utilized
due
to
mass
transfer
limitation,
severely
restricting
their
intrinsic
ORR
properties.
Herein,
a
self-sacrificing
template
strategy
is
developed
fabricate
ultrathin
nanosheets
assembled
Fe1
-N-C
hollow
microspheres
(denoted
as
/N-HCMs)
by
rational
carbonization
of
Fe3+
chelating
polydopamine
coated
melamine
cyanuric
acid
complex.
The
shell
/N-HCMs
constructed
with
thickness
only
2
nm,
which
supposed
an
ideal
platform
isolate
and
expose
metal
atoms.
Benefiting
from
unique
hierarchical
architecture
highly
open
porous
structure,
nm-thick
nanosheet
subunits
abundant
Fe-N4
O1
active
sites
revealed
X-ray
absorption
fine
structure
analysis,
exhibit
high
performance
positive
half-wave
potential
0.88
V
versus
reversible
hydrogen
electrode
robust
stability.
When
served
air-cathode
catalysts
ultralow
loading
0.25
mg
cm-2
,
based
Zn-air
batteries
present
maximum
power
density
187
mW
discharge
specific
capacity
806
mA
h
gZn-1
primary
batteries,
all
exceeding
those
commercial
Pt/C.
SusMat,
Journal Year:
2024,
Volume and Issue:
4(3)
Published: May 8, 2024
Abstract
Although
zinc‒air
batteries
(ZABs)
are
regarded
as
one
of
the
most
prospective
energy
storage
devices,
their
practical
application
has
been
restricted
by
poor
air
electrode
performance.
Herein,
we
developed
a
free‐standing
that
is
fabricated
on
basis
multifunctional
three‐dimensional
interconnected
graphene
network.
Specifically,
network
with
fast
mass
and
electron
transport
ability,
prepared
catalyzing
growth
foam
nickel
then
filling
reduced
oxide
into
pores
foam,
used
to
anchor
iron
phthalocyanine
molecules
atomic
Fe‒N
4
sites
for
boosting
oxygen
reduction
during
discharging
nanosized
FeNi
hydroxides
accelerating
evolution
charging.
As
result,
obtained
exhibited
an
ultra‐small
electrocatalytic
overpotential
0.603
V
reactions,
high
peak
power
density
220.2
mW
cm
‒2
,
small
stable
charge‒discharge
voltage
gap
0.70
at
10
mA
after
1136
cycles.
Furthermore,
in
situ
Raman
spectroscopy
together
theoretical
calculations
confirmed
phase
transformation
takes
place
from
α‐Ni(OH)
x
β‐Ni(OH)
γ‐Ni
(3+δ)+
OOH
reaction
Ni
active
center
while
Fe
enhances
activity
sites.
Small,
Journal Year:
2024,
Volume and Issue:
20(28)
Published: May 6, 2024
Abstract
Neutral
electrolysis
to
produce
hydrogen
is
prime
challenging
owing
the
sluggish
kinetics
of
water
dissociation
for
electrochemical
reduction
molecular
hydrogen.
An
ion‐enriched
electrode/electrolyte
interface
electrocatalytic
reactions
can
efficiently
obtain
a
stable
system.
Herein,
we
found
that
interfacial
accumulated
fluoride
ions
and
anchored
Pt
single
atoms/nanoparticles
in
catalysts
improve
evolution
reaction
(HER)
activity
NiFe‐based
hydroxide
catalysts,
prolonging
operating
stability
at
high
current
density
neutral
conditions.
NiFe
electrode
obtains
an
outstanding
performance
1000
mA
cm
−2
low
overpotential
218
mV
with
h
operation
100
.
Electrochemical
experiments
theoretical
calculations
have
demonstrated
contributes
promote
adsorption
proton
sustaining
large
potential,
while
provide
H
sites.
The
synergy
effect
F
species
promotes
formation
Pt─H
F─H
bonds,
which
accelerate
process
2
O
HER
long‐term
durability
Small,
Journal Year:
2023,
Volume and Issue:
20(6)
Published: Oct. 5, 2023
Abstract
It
is
challenging
yet
promising
to
design
highly
accessible
N‐doped
carbon
skeletons
fully
expose
the
active
sites
inside
single‐atom
catalysts.
Herein,
mesoporous
hollow
spheres
with
regulatable
through‐pore
size
can
be
formulated
by
a
simple
sequential
synthesis
procedure,
in
which
condensed
SiO
2
acted
as
removable
dual‐templates
produce
both
interiors
and
through‐pores,
meanwhile,
co‐condensed
polydopamine
shell
served
precursor.
After
that,
Fe─N─C
(HSs)
obtained
after
rationally
implanting
Fe
single‐atoms.
Microstructural
analysis
X‐ray
absorption
fine
structure
reveal
that
high‐density
Fe─N
4
together
tiny
clusters
are
uniformly
distributed
on
skeleton
abundant
through‐pores.
Benefitted
from
arising
unique
architecture,
HSs
demonstrate
excellent
oxygen
reduction
reaction
(ORR)
performance
alkaline
media
half‐wave
potential
up
0.90
V
versus
RHE
remarkable
stability,
exceeding
commercial
Pt/C.
When
employing
air‐cathode
catalysts,
assembled
Zn–air
batteries
deliver
high
peak
power
density
of
204
mW
cm
−2
stable
discharging
voltage
plateau
over
140
h.
