Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(50)
Published: Nov. 7, 2023
Herein,
the
exposure
of
highly-active
nitrogen
cation
sites
has
been
accomplished
by
photo-driven
quasi-topological
transformation
a
1,10-phenanthroline-5,6-dione-based
covalent
organic
framework
(COF),
which
contributes
to
hydrogen
peroxide
(H2
O2
)
synthesis
during
2-electron
photoreduction.
The
exposed
with
photo-enhanced
Lewis
acidity
not
only
act
as
electron-transfer
motor
adjust
inherent
charge
distribution,
powering
continuous
and
stable
separation,
broadening
visible-light
adsorption,
but
also
providing
large
number
active
for
adsorption.
optimal
catalyst
shows
high
H2
production
rate
11965
μmol
g-1
h-1
under
visible
light
irradiation
remarkable
apparent
quantum
yield
12.9
%
at
400
nm,
better
than
most
previously
reported
COF
photocatalysts.
This
work
provides
new
insights
designing
photo-switchable
catalytic
centers
toward
efficient
solar
chemical
energy
conversion.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Aug. 28, 2023
Constructing
photocatalytically
active
and
stable
covalent
organic
frameworks
containing
both
oxidative
reductive
reaction
centers
remain
a
challenge.
In
this
study,
benzotrithiophene-based
with
spatially
separated
redox
are
rationally
designed
for
the
photocatalytic
production
of
hydrogen
peroxide
from
water
oxygen
without
sacrificial
agents.
The
triazine-containing
framework
demonstrates
high
selectivity
H2O2
photogeneration,
yield
rate
2111
μM
h-1
(21.11
μmol
1407
g-1
h-1)
solar-to-chemical
conversion
efficiency
0.296%.
Codirectional
charge
transfer
large
energetic
differences
between
linkages
linkers
verified
in
double
donor-acceptor
structures
periodic
frameworks.
sites
mainly
concentrated
on
electron-acceptor
fragments
near
imine
bond,
which
regulate
electron
distribution
adjacent
carbon
atoms
to
optimally
reduce
Gibbs
free
energy
O2*
OOH*
intermediates
during
formation
H2O2.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(5), P. 2975 - 2984
Published: Jan. 25, 2023
Multicomponent
reactions
(MCRs)
can
be
used
to
introduce
different
functionalities
into
highly
stable
covalent
organic
frameworks
(COFs).
In
this
work,
the
irreversible
three-component
Doebner
reaction
is
utilized
synthesize
four
chemically
quinoline-4-carboxylic
acid
DMCR-COFs
(DMCR-1-3
and
DMCR-1NH)
equipped
with
an
acid-base
bifunctionality.
These
show
superior
photocatalytic
H2O2
evolution
(one
of
most
important
industrial
oxidants)
compared
imine
COF
analogue
(Imine-1).
This
achieved
sacrificial
oxidants
but
also
in
pure
water
under
oxygen
or
air
atmosphere.
Furthermore,
high
photostability,
durability,
recyclability.
MCR-COFs
thus
provide
a
viable
materials'
platform
for
solar
chemical
energy
conversion.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(19)
Published: March 10, 2023
Four
highly
porous
covalent
organic
frameworks
(COFs)
containing
pyrene
units
were
prepared
and
explored
for
photocatalytic
H2
O2
production.
The
experimental
studies
are
complemented
by
density
functional
theory
calculations,
proving
that
the
unit
is
more
active
production
than
bipyridine
(diarylamino)benzene
reported
previously.
decomposition
experiments
verified
distribution
of
over
a
large
surface
area
COFs
plays
an
important
role
in
catalytic
performance.
Py-Py-COF
though
contains
other
which
induces
high
due
to
dense
concentration
close
proximity
limited
area.
Therefore,
two-phase
reaction
system
(water-benzyl
alcohol)
was
employed
inhibit
decomposition.
This
first
report
on
applying
pyrene-based
generation.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(26)
Published: April 25, 2023
Abstract
Photocatalytic
oxygen
reduction
reaction
(ORR)
offers
a
promising
hydrogen
peroxide
(H
2
O
)
synthetic
strategy,
especially
the
one‐step
two‐electron
(2e
−
ORR
route
holds
great
potential
in
achieving
highly
efficient
and
selectivity.
However,
2e
is
rarely
harvested
underlying
mechanism
for
regulating
pathways
remains
greatly
obscure.
Here,
by
loading
sulfone
units
into
covalent
organic
frameworks
(FS‐COFs),
we
present
an
photocatalyst
H
generation
via
from
pure
water
air.
Under
visible
light
irradiation,
FS‐COFs
exert
superb
yield
of
3904.2
μmol
h
−1
g
,
outperforming
most
reported
metal‐free
catalysts
under
similar
conditions.
Experimental
theoretical
investigation
reveals
that
accelerate
separation
photoinduced
electron‐hole
(e
‐h
+
pairs,
enhance
protonation
COFs,
promote
adsorption
Yeager‐type,
which
jointly
alters
process
two‐step
to
one,
thereby
with
high
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(9)
Published: Dec. 30, 2022
The
full
reaction
photosynthesis
of
H2
O2
that
can
combine
water-oxidation
and
oxygen-reduction
without
sacrificial
agents
is
highly
demanded
to
maximize
the
light-utilization
overcome
complex
reaction-process
anthraquinone-oxidation.
Here,
a
kind
oxidation-reduction
molecular
junction
covalent-organic-framework
(TTF-BT-COF)
has
been
synthesized
through
covalent-coupling
tetrathiafulvalene
(photo-oxidation
site)
benzothiazole
(photo-reduction
site),
which
presents
visible-light-adsorption
region,
effective
electron-hole
separation-efficiency
photo-redox
sites
enables
generation
.
Specifically,
record-high
yield
(TTF-BT-COF,
≈276
000
μM
h-1
g-1
)
for
achieved
among
porous
crystalline
photocatalysts.
This
first
work
design
COFs
,
might
extend
scope
in
production.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(49)
Published: Aug. 14, 2023
Abstract
Benefiting
from
the
excellent
structural
tunability,
robust
framework,
ultrahigh
porosity,
and
rich
active
sites,
covalent
organic
frameworks
(COFs)
are
widely
recognized
as
promising
photocatalysts
in
chemical
conversions,
emerged
hydrogen
peroxide
(H
2
O
)
photosynthesis
2020.
H
,
serving
an
environmental‐friendly
oxidant
a
liquid
fuel,
has
attracted
increasing
researchers
to
explore
its
potential.
Over
past
few
years,
numerous
COFs‐based
developed
with
encouraging
achievements
production,
whereas
no
comprehensive
review
articles
exist
summarize
this
specific
significant
area.
Herein
we
provide
systematic
overview
of
advances
challenges
COFs
photocatalytic
production.
We
first
introduce
priorities
photosynthesis.
Then,
various
strategies
improve
efficiency
discussed.
The
perspective
outlook
for
future
emerging
field
finally
offered.
This
timely
will
pave
way
development
highly
efficient
practical
production
value‐added
chemicals
not
limited
.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(9)
Published: Dec. 28, 2022
Covalent
organic
frameworks
(COFs)
are
highly
desirable
for
achieving
high-efficiency
overall
photosynthesis
of
hydrogen
peroxide
(H2
O2
)
via
molecular
design.
However,
precise
construction
COFs
toward
photosynthetic
H2
remains
a
great
challenge.
Herein,
we
report
the
crystalline
s-heptazine-based
(HEP-TAPT-COF
and
HEP-TAPB-COF)
with
separated
redox
centers
efficient
production
from
pure
water.
The
spatially
orderly
active
sites
in
HEP-COFs
can
efficiently
promote
charge
separation
enhance
photocatalytic
production.
Compared
HEP-TAPB-COF,
HEP-TAPT-COF
exhibits
higher
efficiency
integrating
dual
reduction
s-heptazine
triazine
moieties.
Accordingly,
bearing
remarkable
solar-to-chemical
energy
0.65
%
high
apparent
quantum
15.35
at
420
nm,
surpassing
previously
reported
COF-based
photocatalysts.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(34)
Published: April 24, 2023
Abstract
Intensifying
energy
crises
and
severe
environmental
issues
have
led
to
the
discovery
of
renewable
sources,
sustainable
conversion,
storage
technologies.
Photocatalysis
is
a
green
technology
that
converts
eco‐friendly
solar
into
high‐energy
chemicals.
Covalent
organic
frameworks
(COFs)
are
porous
materials
constructed
by
covalent
bonds
show
promising
potential
for
converting
chemicals
owing
their
pre‐designable
structures,
high
crystallinity,
porosity.
Herein,
we
highlight
recent
progress
in
synthesis
COF‐based
photocatalysts
applications
water
splitting,
CO
2
reduction,
H
O
production.
The
challenges
future
opportunities
rational
design
COFs
advanced
discussed.
This
Review
expected
promote
further
development
toward
photocatalysis.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(38)
Published: Aug. 1, 2023
H2
O2
is
a
significant
chemical
widely
utilized
in
the
environmental
and
industrial
fields,
with
growing
global
demand.
Without
sacrificial
agents,
simultaneous
photocatalyzed
synthesis
through
oxygen
reduction
reaction
(ORR)
water
oxidation
(WOR)
dual
channels
from
seawater
green
sustainable
but
still
challenging.
Herein,
two
novel
thiophene-containing
covalent
organic
frameworks
(TD-COF
TT-COF)
were
first
constructed
served
as
catalysts
for
via
indirect
2e-
ORR
direct
WOR
channels.
The
photocatalytic
production
performance
can
be
regulated
by
adjusting
N-heterocycle
modules
(pyridine
triazine)
COFs.
Notably,
no
just
using
air
raw
materials,
TD-COF
exhibited
high
yields
of
4060
μmol
h-1
g-1
3364
deionized
natural
seawater,
respectively.
Further
computational
mechanism
studies
revealed
that
thiophene
was
primary
photoreduction
unit
ORR,
while
benzene
ring
(linked
to
imine
bond)
central
photooxidation
WOR.
current
work
exploits
COFs
overall
provides
fresh
insight
into
creating
innovative
photocatalyzing
synthesis.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Oct. 28, 2023
Developing
efficient
artificial
photocatalysts
for
the
biomimetic
photocatalytic
production
of
molecular
materials,
including
medicines
and
clean
energy
carriers,
remains
a
fundamentally
technologically
essential
challenge.
Hydrogen
peroxide
is
widely
used
in
chemical
synthesis,
medical
disinfection,
energy.
However,
current
industrial
production,
predominantly
by
anthraquinone
oxidation,
suffers
from
hefty
penalties
toxic
byproducts.
Herein,
we
report
hydrogen
protonation-induced
dispersible
porous
polymers
with
good
charge-carrier
transport
properties.
Significant
generation
occurs
under
ambient
conditions
at
an
unprecedented
rate
23.7
mmol
g-1
h-1
apparent
quantum
efficiency
11.3%
450
nm.
Combined
simulations
spectroscopies
indicate
that
sub-picosecond
ultrafast
electron
"localization"
both
free
carriers
exciton
states
catalytic
reaction
centers
underlie
remarkable
performance
polymers.