Heterogeneity
engineering
provides
an
effective
route
to
manipulate
the
chemical
and
physical
properties
of
covalent
organic
frameworks
(COFs)
but
is
still
under
development
for
their
single-crystal
form.
Here,
we
report
strategy
based
on
a
combination
template-assisted
modulated
synthesis
with
one-pot
crystallization-reduction
method
directly
construct
ordered
macro-microporous
single
crystals
amine-linked
three-dimensional
(3D)
COF
(OM-COF-300-SR).
In
this
strategy,
colloidal
crystal-templating
not
only
assists
formation
macropores
also
greatly
facilitates
in
situ
conversion
linkages
(from
imine
amine)
COF-300
crystals.
The
as-synthesized
OM-COF-300-SR120
exhibits
reversible
symmetry
change
from
tetragonal
I41/a
monoclinic
I2/c
space
group
after
activation,
which
was
observed
previously.
On
other
hand,
allows
flexible
control
over
degree
amination
0
100%,
as
determined
by
X-ray
photoelectron
spectroscopy
(XPS)
analysis)
regulate
band
gap
2.57
2.81
eV)
optimization
photocatalytic
activity.
high
embedded
render
superior
activity
(with
reaction
rate
constant
0.9572
min-1)
its
nonmacroporous
counterpart
(NM-COF-300-SR120,
0.2303
degradation
rhodamine
B.
addition,
significant
contribution
confront
mass
transfer
resistance
confirmed
much
higher
catalytic
Au/OM-COF-300-SR120
parameter
7.96
×
103
s-1
mol-1)
compared
Au/NM-COF-300-SR120
(1.43
model
reduction
4-nitrophenol
NaBH4.
ACS Applied Nano Materials,
Journal Year:
2024,
Volume and Issue:
7(22), P. 25675 - 25692
Published: Nov. 1, 2024
The
rapid
development
of
human
civilization
has
influenced
the
rising
demand
for
sustainable
energy
sources,
and
deteriorating
air
quality
elevated
risk
toxic-gas
exposure.
This
encourages
efficient
nanomaterials
capable
seamlessly
combining
multiple
functions
adapting
to
various
application
areas.
However,
establishing
a
generalized
strategy
achieving
multipurpose
applications
always
been
challenge.
Herein,
type-II
heterojunction
designed
with
BiFeO3
nanoparticles
embedded
on
α-MoO3
nanorods
demonstrate
highly
multifunctional
properties
photocatalytic
activity
gas
sensing.
optimized
heterostructure
exhibits
∼8.3-folds
higher
current
density
(∼12
μA/cm2)
12-folds
enhanced
H2
generation
(340
μmol
g–1)
under
visible-light
irradiation,
surpassing
benchmark
MoO3-based
systems.
Moreover,
145%
improvement
in
H2S
sensing
performance
(∼98%
100
ppm)
response/recovery
time
4.7/14
s
achieved.
proposed
growth
mechanism
suggests
that,
sitting
top
facilitate
formation
interface,
creating
defects
system
overcome
shortcomings
bare
as
water-splitting
catalyst.
Band-edge
modification
(with
wide-band-gap
nanorods,
narrow-band-gap
nanoparticles)
tuned
oxygen
vacancy
concentration
have
synergetic
effect
performance.
A
potential
gradient
at
interface
two
semiconductors
generates
built-in
electric
field
facilitating
charge
transfer,
reflected
lower
Rct
value.
vacancies
act
electron
traps,
which
reduce
recombination
improve
absorption.
Consequently,
it
boosts
efficiency
creates
myriads
active
sites
adsorption.
work
provides
route
designing
band-gap-engineered
α-MoO3/BiFeO3
that
originated
from
enriched
address
need
green-energy
environmental
air-quality
monitoring.
Heterogeneity
engineering
provides
an
effective
route
to
manipulate
the
chemical
and
physical
properties
of
covalent
organic
frameworks
(COFs)
but
is
still
under
development
for
their
single-crystal
form.
Here,
we
report
strategy
based
on
a
combination
template-assisted
modulated
synthesis
with
one-pot
crystallization-reduction
method
directly
construct
ordered
macro-microporous
single
crystals
amine-linked
three-dimensional
(3D)
COF
(OM-COF-300-SR).
In
this
strategy,
colloidal
crystal-templating
not
only
assists
formation
macropores
also
greatly
facilitates
in
situ
conversion
linkages
(from
imine
amine)
COF-300
crystals.
The
as-synthesized
OM-COF-300-SR120
exhibits
reversible
symmetry
change
from
tetragonal
I41/a
monoclinic
I2/c
space
group
after
activation,
which
was
observed
previously.
On
other
hand,
allows
flexible
control
over
degree
amination
0
100%,
as
determined
by
X-ray
photoelectron
spectroscopy
(XPS)
analysis)
regulate
band
gap
2.57
2.81
eV)
optimization
photocatalytic
activity.
high
embedded
render
superior
activity
(with
reaction
rate
constant
0.9572
min-1)
its
nonmacroporous
counterpart
(NM-COF-300-SR120,
0.2303
degradation
rhodamine
B.
addition,
significant
contribution
confront
mass
transfer
resistance
confirmed
much
higher
catalytic
Au/OM-COF-300-SR120
parameter
7.96
×
103
s-1
mol-1)
compared
Au/NM-COF-300-SR120
(1.43
model
reduction
4-nitrophenol
NaBH4.
