ACS ES&T Engineering,
Год журнала:
2022,
Номер
2(10), С. 1776 - 1796
Опубликована: Сен. 7, 2022
Single
atom
catalysts
(SACs)
have
emerged
as
a
promising
catalyst
material
architecture
for
energy,
chemical,
and
environmental
applications.
In
the
past
several
years,
SACs
been
increasingly
explored
persulfate-based
advanced
oxidation
processes
(AOPs)
due
to
their
superior
persulfate
activation
pollutant
degradation
performance
compared
benchmark
dissolved
ion
nanoparticle
catalysts.
However,
there
still
exist
uncertainties
on
mechanism
of
by
SACs,
which
involves
complex
interplay
sulfate
hydroxyl
radicals,
singlet
oxygen,
high-valent
metal
species,
and/or
mediated
electron
transfer.
Questions
also
remain
how
ions
molecularly
align
single
site,
are
converted
into
reactive
what
design
parameters
lead
higher
efficiency
degradation.
this
critical
review,
we
examine
SAC
materials
employed
AOPs
discuss
they
function
differently
counterparts.
We
further
our
discussion
current
limitations,
opportunities,
future
research
needs
in
(i)
filling
knowledge
gaps
mechanisms
persulfate-SAC
interactions;
(ii)
augmenting
fundamental
with
theoretical
simulation
situ
characterization
techniques;
(iii)
improving
tailored
applications;
(iv)
proactively
considering
challenges
associated
engineering
practices
water
matrixes.
Environmental Science & Technology,
Год журнала:
2021,
Номер
55(18), С. 12640 - 12651
Опубликована: Авг. 31, 2021
Herein,
we
report
that
Co(II)-doped
g-C3N4
can
efficiently
trigger
peracetic
acid
(PAA)
oxidation
of
various
sulfonamides
(SAs)
in
a
wide
pH
range.
Quite
different
from
the
traditional
radical-generating
or
typical
nonradical-involved
(i.e.,
singlet
oxygenation
and
mediated
electron
transfer)
catalytic
systems,
PAA
activation
follows
novel
nonradical
pathway
with
unprecedented
high-valent
cobalt–oxo
species
[Co(IV)]
as
dominant
reactive
species.
Our
experiments
density
functional
theory
calculations
indicate
Co
atom
fixated
into
nitrogen
pots
serves
main
active
site,
enabling
dissociation
adsorbed
conversion
coordinated
Co(II)
to
Co(IV)
via
unique
two-electron
transfer
mechanism.
Considering
be
highly
electrophilic
nature,
substituents
five-membered
six-membered
heterocyclic
moieties)
on
SAs
could
affect
their
nucleophilicity,
thus
leading
differences
degradation
efficiency
transformation
pathway.
Also,
benefiting
selective
Co(IV),
established
oxidative
system
exhibits
excellent
anti-interference
capacity
achieves
satisfactory
decontamination
performance
under
actual
water
conditions.
This
study
provides
new
approach
degrade
by
activating
heterogeneous
cobalt-complexed
catalysts.
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(9), С. 5611 - 5619
Опубликована: Апрель 20, 2022
Rapid
generation
of
high-valent
cobalt-oxo
species
(Co(IV)═O)
for
the
removal
organic
contaminants
has
been
challenging
because
low
conversion
efficiency
Co(III)/Co(II)
and
high
activation
energy
barrier
Co(II)-oxidant
complex.
Herein,
we
introduced
nitrogen
(N)
vacancies
into
graphite
carbon
nitride
imbedded
with
cobalt
carbonate
(CCH/CN–Vn)
in
a
peroxymonosulfate
(PMS)/visible
light
system
to
break
limitations
conventional
two-electron
transfer
path.
These
N
enhanced
electron
distribution
Co
3d
orbital
lowered
cleave
O–O
bond
PMS
Co(II)-PMS
complex,
achieving
modulation
major
active
from
1O2
Co(IV)═O.
The
developed
synergistic
that
exhibited
adsorption
oxidation
showed
remarkable
selectivity
contaminant
performance
inorganic
(Cl–,
NO3–,
HCO3–,
HPO4–)
(HA)
even
practical
aqueous
matrices
(tap
water
secondary
effluent).
This
study
provides
novel
mechanistic
perspective
modulate
nonradical
path
refractory
treatment
via
defect
engineering.
Environmental Science & Technology,
Год журнала:
2022,
Номер
56(12), С. 8984 - 8992
Опубликована: Май 31, 2022
In
persulfate
activation
by
copper-based
catalysts,
high-valent
copper
(Cu(III))
is
an
overlooked
reactive
intermediate
that
contributes
to
efficient
utilization
and
organic
pollutant
removal.
However,
the
mechanisms
underlying
heterogeneous
enhanced
are
not
fully
understood.
Here,
oxide
(CuO)
nanosheets
(synthesized
with
a
facile
precipitation
method)
exhibited
high
catalytic
activity
for
peroxymonosulfate
(PMS)
100%
4-chlorophenol
(4-CP)
degradation
within
3
min.
Evidence
critical
role
of
surface-associated
Cu(III)
on
PMS
4-CP
over
wide
pH
range
(pH
3-10)
was
obtained
using
in
situ
Raman
spectroscopy,
electron
paramagnetic
resonance,
quenching
tests.
directly
oxidized
other
phenolic
pollutants,
rate
constants
inversely
proportional
their
ionization
potentials.
preferentially
oxidizes
rather
than
react
two
molecules
generate
one
molecule
1O2,
thus
minimizing
this
less
pathway.
Accordingly,
much
higher
efficiency
(77%
electrons
accepted
ascribed
mineralization)
CuO/PMS
radical
pathway-dominated
Co3O4/PMS
system
(27%)
or
1O2
α-MnO2/PMS
(26%).
Overall,
these
results
highlight
potential
benefits
via
oxidation
offer
mechanistic
insight
into
ultrahigh
Proceedings of the National Academy of Sciences,
Год журнала:
2023,
Номер
120(16)
Опубликована: Апрель 11, 2023
The
high-valent
cobalt-oxo
species
(Co(IV)=O)
is
being
increasingly
investigated
for
water
purification
because
of
its
high
redox
potential,
long
half-life,
and
antiinterference
properties.
However,
generation
Co(IV)=O
inefficient
unsustainable.
Here,
a
cobalt-single-atom
catalyst
with
N/O
dual
coordination
was
synthesized
by
O-doping
engineering.
O-doped
(Co-OCN)
greatly
activated
peroxymonosulfate
(PMS)
achieved
pollutant
degradation
kinetic
constant
73.12
min-1
g-2,
which
4.9
times
higher
than
that
Co-CN
(catalyst
without
O-doping)
those
most
reported
single-atom
catalytic
PMS
systems.
Co-OCN/PMS
realized
dominant
oxidation
pollutants
increasing
the
steady-state
concentration
(1.03
×
10-10
M)
5.9
compared
Co-CN/PMS.
A
competitive
kinetics
calculation
showed
contribution
to
micropollutant
97.5%
during
process.
Density
functional
theory
calculations
influenced
charge
density
(increased
Bader
transfer
from
0.68
0.85
e),
optimized
electron
distribution
Co
center
d-band
-1.14
-1.06
eV),
enhanced
adsorption
energy
-2.46
-3.03
eV,
lowered
barrier
key
reaction
intermediate
(*O*H2O)
formation
1.12
0.98
eV.
Co-OCN
fabricated
on
carbon
felt
flow-through
device,
continuous
efficient
removal
micropollutants
(degradation
efficiency
>85%
after
36
h
operation).
This
study
provides
new
protocol
activation
elimination
through
heteroatom-doping
metal-oxo
purification.
