ACS Materials Letters,
Год журнала:
2024,
Номер
unknown, С. 393 - 400
Опубликована: Дек. 26, 2024
The
intrinsic
structural
advantages
and
tunability
of
covalent
organic
frameworks
(COFs)
have
made
them
promising
photocatalysts
for
various
photocatalytic
reactions.
However,
it
remains
a
great
challenge
to
systematically
tune
the
linker
lengths
build
linker-length-dependent
structure-performance
relationship
COFs-based
photocatalysts.
Herein,
five
isoreticular
COFs
with
sql
underlying
nets
been
successfully
synthesized
using
benzothiadiazole-based
ditopic
aldehydes
varied
1,3,6,8-tetrakis(4-aminophenyl)pyrene
as
building
units.
obtained
exhibit
significantly
different
activities
toward
aerobic
oxidation.
Remarkably,
COF-containing
vinyl
group,
HIAM-0020,
exhibited
best
performance
near-unity
conversion
selectivity
oxidative
benzylamine
coupling
within
2
h.
experimental
theoretical
investigations
indicate
that
HIAM-0020
exhibits
faster
charge
separation
ability
lower
migration
resistance
compared
other
four
COFs.
This
work
represents
guidance
rational
design
synthesis
COF-based
achieve
efficient
transformation.
Advanced Energy Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 3, 2025
Abstract
The
artificial
photosynthesis
of
hydrogen
peroxide
(H
2
O
)
using
semiconductor
photocatalysts
is
gaining
attention
as
an
eco‐friendly
and
energy‐efficient
method.
Covalent
organic
frameworks
(COFs)
show
great
promise
in
enhancing
photocatalytic
H
production
due
to
their
tunable
structures
functional
diversity.
However,
the
efficiency
generation
close
photoelectric
properties
COFs
microenvironment
active
sites.
Herein,
synthesis
pyridyl‐imine‐functionalized
(PyIm‐COFs)
featuring
donor–acceptor
(D–A)
moieties
improve
reported.
By
employing
benzothiadiazole
(BT)
units
with
varied
fluorine
substitutions,
electronic
environment
sites,
optimizing
selective
two‐electron
(2e
−
oxygen
reduction
reaction
(ORR),
tuned.
Among
synthesized
COFs,
PyIm‐BT_F
exhibits
highest
activity,
achieving
a
rate
5342
µmol
g
−1
h
.
importance
D–A
rational
design
COF‐based
photocatalysts,
providing
novel
strategy
for
sustainable
through
optimized
site
environments,
underscored.
Chemical Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
A
terpolymer
photocatalyst
containing
an
ultra-low
ratio
of
BT
showed
ultra-fast
electron
transfer
and
drastically
lowered
exciton
binding
energy,
resulting
in
a
hydrogen
evolution
rate
up
to
222.28
mmol
h
−1
g
without
the
aid
Pt
co-catalysts.
ACS Catalysis,
Год журнала:
2024,
Номер
unknown, С. 17654 - 17663
Опубликована: Ноя. 15, 2024
The
photosynthesis
of
hydrogen
peroxide
(H2O2)
from
pure
water
and
oxygen
using
metal-free
photocatalysts
offers
a
renewable
approach
to
convert
solar
energy
storable
chemical
energy.
However,
the
efficiency
H2O2
is
often
hindered
by
rapid
recombination
photogenerated
charge
carriers.
Herein,
we
present
an
elegantly
designed
covalent
triazine
framework
(CTF)
photocatalyst,
denoted
as
Ace-asy-CTF,
with
stepwise
electron
transfer
pathway
for
highly
efficient
H2O2.
Notably,
Ace-asy-CTF
possesses
localized
excited-state
distribution
that
created
weakly
conjugated
acetenyl
units
in
asymmetric
frameworks,
revealed
transient
spectroscopies
further
supported
theoretical
calculations.
Meanwhile,
introduced
also
serve
active
sites
reduction
reaction
(ORR).
simultaneously
enhanced
two-step
2e–
ORR
result
excellent
yield
2594
μmol
g–1
h–1,
directly
produced
without
requiring
any
sacrificial
reagents.
This
work
paves
way
development
next-generation
catalysts,
providing
feasible
benchmark
stable
Abstract
Covalent
organic
frameworks
(COFs)
have
emerged
as
one
of
the
most
studied
photocatalysts
owing
to
their
adjustable
structure
and
bandgaps.
However,
there
is
limited
research
on
regulating
light‐harvesting
capabilities
acceptor
building
blocks
in
donor–acceptor
(D–A)
isomer
COFs
with
different
bond
orientations.
This
investigation
crucial
for
elucidating
structure‐property‐performance
relationship
COF
photocatalysts.
Herein,
a
series
D–A
isostructural
are
synthesized
imine
orientations
using
benzothiadiazole
its
derivatives‐based
units.
Extended
light
absorption
achieved
groups
that
strong
electron‐withdrawing
capacities,
although
this
resulted
decreased
hydrogen
generation
efficiency.
Photocatalytic
experiments
indicated
dialdehyde
benzothiadiazole‐based
COFs,
HIAM‐0015,
exhibit
highest
rate
(17.99
mmol
g
−1
h
),
which
15
times
higher
than
isomer.
The
excellent
photocatalytic
performance
HIAM‐0015
can
be
attributed
fast
charge
separation
migration.
work
provides
insights
into
rational
design
synthesis
achieve
efficient
activity.
Applied Organometallic Chemistry,
Год журнала:
2025,
Номер
39(2)
Опубликована: Янв. 9, 2025
ABSTRACT
A
D‐A
1
‐A
2
type
covalent
triazine
framework
(CTF)
was
prepared
for
the
photocatalytic
hydrogen
evolution
(HER).
In
resulting
CTF‐CZ‐Bpy
2+
,
9‐ethyl‐9
H
‐carbazole
(CZ)
group
is
used
as
donor,
ring
first
acceptor,
and
cyclic
diquat
(Bpy
)
moiety
second
acceptor.
Both
experimental
theoretical
results
show
that
structure
significantly
enhances
efficiency
of
photogenerated
charge
separation
transfer.
As
a
result,
demonstrated
outstanding
HER
activity
with
yield
rate
31.1
mmol
g
−1
h
which
7.8
times
higher
than
nonfunctionalized
CTF‐CZ‐Bpy.
Advanced Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 18, 2025
Abstract
Cyano‐functionalized
sp
2
‐carbon‐conjugated
covalent
organic
frameworks
(CN‐COFs)
have
been
considered
as
promising
candidates
for
artificial
photosynthesis
of
hydrogen
peroxide
(H
O
).
Nevertheless,
the
performance
CN‐COFs
is
inherently
limited
by
constrained
oxygen
capture
capacity,
insufficient
charge
separation,
and
rapid
carrier
recombination.
Herein,
study
rationally
reports
a
strategy
integrating
amidoxime
groups
(AO)
into
COF
through
one‐step
cyano
hydrolysis
process
to
increase
photocatalytic
H
production.
Combined
simulations
characterizations
reveal
that
introducing
AO
enhances
hydrophilicity,
stabilizes
adsorbed
Oxygen
(O
)
via
bonding,
accelerates
separation
transfer,
well
lowers
energy
barrier
reduction
reaction
pathway,
thus
achieving
an
unmatched
production
rate
6024
µmol
h
−1
g
.
Importantly,
solar‐to‐chemical
conversion
(SCC)
efficiency
PTTN‐AO
reaches
0.61%,
significantly
surpassing
natural
plants
(≈0.1%)
most
COF‐based
photocatalysts.
The
current
findings
are
encouraging
molecular
design
polymers
green
efficient
