ACS Nano,
Год журнала:
2023,
Номер
17(8), С. 7584 - 7594
Опубликована: Апрель 7, 2023
Covalent
organic
framework
(COF)
membranes
have
emerged
as
a
promising
candidate
for
energy-efficient
separations,
but
the
angstrom-precision
control
of
channel
size
in
subnanometer
region
remains
challenge
that
has
so
far
restricted
their
potential
gas
separation.
Herein,
we
report
an
ultramicropore-in-nanopore
concept
engineering
matreshka-like
pore-channels
inside
COF
membrane.
In
this
concept,
α-cyclodextrin
(α-CD)
is
situ
encapsulated
during
interfacial
polymerization
which
presumably
results
linear
assembly
(LA)
α-CDs
1D
nanochannels
COF.
The
LA-α-CD-in-TpPa-1
membrane
shows
high
H2
permeance
(∼3000
GPU)
together
with
enhanced
selectivity
(>30)
over
CO2
and
CH4
due
to
formation
fast
selective
H2-transport
pathways.
overall
performance
H2/CO2
H2/CH4
separation
transcends
Robeson
upper
bounds
ranks
among
most
powerful
H2-selective
membranes.
versatility
strategy
demonstrated
by
synthesizing
different
types
LA-α-CD-in-COF
The Innovation,
Год журнала:
2021,
Номер
2(1), С. 100076 - 100076
Опубликована: Янв. 10, 2021
Covalent
organic
frameworks
(COFs)
are
a
new
type
of
crystalline
porous
polymers
known
for
chemical
stability,
excellent
structural
regularity,
robust
framework,
and
inherent
porosity,
making
them
promising
materials
capturing
various
types
pollutants
from
aqueous
solutions.
This
review
thoroughly
presents
the
recent
progress
advances
COFs
COF-based
as
superior
adsorbents
efficient
removal
toxic
heavy
metal
ions,
radionuclides,
pollutants.
Information
about
interaction
mechanisms
between
summarized
macroscopic
microscopic
standpoints,
including
batch
experiments,
theoretical
calculations,
advanced
spectroscopy
analysis.
The
adsorption
properties
assessed
compared
with
other
widely
used
adsorbents.
Several
commonly
strategies
to
enhance
materials'
performance
relationship
property
sorption
ability
also
discussed.
Finally,
summary
perspective
on
opportunities
challenges
proposed
provide
some
inspiring
information
designing
fabricating
environmental
pollution
management.
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Фев. 27, 2023
Covalent
organic
frameworks
(COFs)
represent
an
emerging
class
of
photocatalysts.
However,
their
complicated
structures
lead
to
indeterminacy
about
photocatalytic
active
sites
and
reaction
mechanisms.
Herein,
we
use
reticular
chemistry
construct
a
family
isoreticular
crystalline
hydrazide-based
COF
photocatalysts,
with
the
optoelectronic
properties
local
pore
characteristics
COFs
modulated
using
different
linkers.
The
excited
state
electronic
distribution
transport
pathways
in
are
probed
host
experimental
methods
theoretical
calculations
at
molecular
level.
One
our
developed
(denoted
as
COF-4)
exhibits
remarkable
electron
utilization
efficiency
charge
transfer
properties,
achieving
record-high
uranium
extraction
performance
~6.84
mg/g/day
natural
seawater
among
all
techniques
reported
so
far.
This
study
brings
new
understanding
operation
COF-based
guiding
design
improved
photocatalysts
for
many
applications.
Angewandte Chemie International Edition,
Год журнала:
2020,
Номер
59(52), С. 23845 - 23853
Опубликована: Сен. 21, 2020
Abstract
The
polarity
of
a
semiconducting
molecule
affects
its
intrinsic
photophysical
properties,
which
can
be
tuned
by
varying
the
molecular
geometry.
Herein,
we
developed
D
3
h
‐symmetric
tricyanomesitylene
as
new
monomer
could
reticulated
into
vinylene‐linked
covalent
organic
framework
(g‐C
54
N
6
‐COF)
via
Knoevenagel
condensation
with
another
2,4,6‐tris(4′‐formyl‐biphenyl‐4‐yl)‐1,3,5‐triazine.
Replacing
C
2
v
3,5‐dicyano‐2,4,6‐trimethylpyridine
gave
less‐symmetric
COF
52
‐COF).
octupolar
conjugated
characters
g‐C
‐COF
were
reflected
in
scarce
solvatochromic
effects
either
ground
or
excited
states,
and
endowed
it
more
promising
behavior
compared
‐COF,
such
enhanced
light‐harvesting
excellent
photo‐induced
charge
generation
separation.
Along
matched
energy
level,
enabled
two‐half
reactions
photocatalytic
water
splitting
an
average
O
evolution
rate
51.0
μmol
−1
g
H
2518.9
.
Such
values
are
among
highest
state‐of‐the‐art
photocatalysts.
Chemical Society Reviews,
Год журнала:
2022,
Номер
51(15), С. 6307 - 6416
Опубликована: Янв. 1, 2022
This
review
highlights
the
recent
advances
of
metalated
covalent
organic
frameworks,
including
synthetic
strategies
and
applications,
discusses
current
challenges
future
directions.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(30)
Опубликована: Апрель 29, 2023
Optimizing
the
electronic
structure
of
covalent
organic
framework
(COF)
photocatalysts
is
essential
for
maximizing
photocatalytic
activity.
Herein,
we
report
an
isoreticular
family
multivariate
COFs
containing
chromenoquinoline
rings
in
COF
and
electron-donating
or
withdrawing
groups
pores.
Intramolecular
donor-acceptor
(D-A)
interactions
allowed
tuning
local
charge
distributions
carrier
separation
under
visible
light
irradiation,
resulting
enhanced
performance.
By
optimizing
optoelectronic
properties
COFs,
a
uranium
extraction
efficiency
8.02
mg/g/day
was
achieved
using
nitro-functionalized
multicomponent
natural
seawater,
exceeding
performance
all
reported
to
date.
Results
demonstrate
effective
design
strategy
towards
high-activity
with
intramolecular
D-A
structures
not
easily
accessible
traditional
synthetic
approaches.
Journal of the American Chemical Society,
Год журнала:
2020,
Номер
143(1), С. 369 - 381
Опубликована: Дек. 24, 2020
While
crystalline
covalent
organic
frameworks
(COFs)
linked
by
C–C
bonds
are
highly
desired
in
synthetic
chemistry,
it
remains
a
formidable
challenge
to
synthesize.
Efforts
generate
single
COFs
via
de
novo
synthesis
usually
afford
amorphous
structures
rather
than
phases.
We
demonstrate
here
that
bond-based
can
be
prepared
direct
reduction
of
C═C
bond-linked
crystal-to-crystal
transformation.
By
Knoevenagel
polycondensation
chiral
tetrabenzaldehyde
dibinaphthyl-22-crown-6
with
1,4-phenylenediacetonitrile
or
4,4′-biphenyldiacetonitrile,
two
olefin-linked
2D
layered
tetragonal
structure
prepared.
Reduction
olefin
linkages
the
as-prepared
CCOFs
produces
bond
frameworks,
which
retains
high
crystallinity
and
porosity
as
well
chemical
stability
both
strong
acids
bases.
The
quantitative
is
confirmed
Fourier
transform
infrared
cross-polarization
magic
angle
spinning
13C
NMR
spectroscopy.
Compared
pristine
structures,
reduced
display
blue-shifted
emission
enhanced
quantum
yields
fluorescence
lifetimes,
while
parent
exhibit
higher
enantioselectivity
analogs
when
used
fluorescent
sensors
detect
amino
alcohols
supramolecular
interactions
built-in
crown
ether
moieties.
This
work
provides
an
attractive
strategy
for
making
chemically
stable
functionalized
new
otherwise
hard
produce.
Advanced Materials,
Год журнала:
2022,
Номер
34(17)
Опубликована: Янв. 20, 2022
Abstract
Covalent
organic
frameworks
(COFs),
an
emerging
class
of
crystalline
polymers
with
highly
oriented
structures
and
permanent
porosity,
can
adopt
2D
or
3D
architectures
depending
on
the
different
topological
diagrams
monomers.
Notably,
COFs
have
particularly
gained
much
attention
due
to
extraordinary
merits
their
extended
in‐plane
π‐conjugation
topologically
ordered
columnar
π‐arrays.
These
properties
together
high
crystallinity,
large
surface
area,
tunable
porosity
distinguish
as
ideal
candidate
for
fabrication
functional
materials.
Herein,
this
review
surveys
recent
research
advances
in
special
emphasis
preparation
COF
powders,
single
crystals,
thin
films,
well
advanced
optical,
electrical,
magnetic
functionalities.
Some
challenging
issues
potential
outlook
are
also
provided
promoting
development
terms
structure,
synthesis,
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Июль 19, 2023
Solar-driven
photosynthesis
is
a
sustainable
process
for
the
production
of
hydrogen
peroxide,
efficiency
which
plagued
by
side
reactions.
Metal-free
covalent
organic
frameworks
(COFs)
that
can
form
suitable
intermediates
and
inhibit
reactions
show
great
promise
to
photo-synthesize
H2O2.
However,
insufficient
formation
separation/transfer
photogenerated
charges
in
such
materials
restricts
H2O2
production.
Herein,
we
provide
strategy
design
donor-acceptor
COFs
greatly
boost
photosynthesis.
We
demonstrate
optimal
intramolecular
polarity
COFs,
achieved
using
amounts
phenyl
groups
as
electron
donors,
maximize
free
charge
generation,
leads
high
yield
rates
(605
μmol
g-1
h-1)
from
water,
oxygen
visible
light
without
sacrificial
agents.
Combining
in-situ
characterization
with
computational
calculations,
describe
how
triazine
N-sites
N
2p
states
play
crucial
role
H2O
activation
selective
oxidation
into
further
experimentally
be
efficiently
produced
tap,
river
or
sea
water
natural
sunlight
air
decontamination.
