Real-time
monitoring
of
toxic
gases
can
be
performed
by
metal
oxide
semiconductor-based
chemo-resistive
gas
sensors
due
to
their
simple
structures,
low
cost,
and
faster
better
recovery
response.
Due
the
effective
electron-hole
separation,
tuning
formation
phase
junctions
is
an
efficient
method
for
improving
sensing
properties.
In
this
study,
two
distinct
hydrothermal
methods
were
used
synthesize
h-/m-WO3
hetero-nanoflowers.
first
method,
L-Cysteine
was
facilitate
between
h-WO3
m-WO3
nanostructures,
whereas
Thiourea
in
second.
Various
characterisation
approaches
validated
hexagonal-monoclinic
junction
development
nanoflowers.
The
material
fabricated
using
with
a
concentration
0.01M
than
other
sensors.
At
350°C,
selected
sample
displayed
outstanding
ammonia
capacity
experimental
detection
limit
1
ppm
(response=3.33).
theoretical
determined
27
ppb.
selectivity
sensor
towards
NH3
over
H2S
acetone
increased
combining
devices
double
filtration
setup.
Inorganic Chemistry,
Journal Year:
2024,
Volume and Issue:
63(47), P. 22583 - 22593
Published: Nov. 13, 2024
The
functional
gas
sensor
device
plays
a
pivotal
role
in
intelligent
medical
treatment,
among
which
metal
oxide
semiconductors
are
widely
studied
because
of
their
inexpensiveness
and
ease
fabrication.
However,
the
sensors
present
significant
challenge
detecting
NH3
at
ppm
levels
within
complex
exhaled
gases.
Herein,
ZnO/PdO-x
series
were
prepared
by
situ
loading
palladium
particles
calcining
using
nano-ZIF-8
as
precursor,
not
only
provided
more
transport
path
for
ammonia
adsorption
but
also
achieved
homogeneous
nanoheterojunction
accumulation
structure.
tailor-made
ZnO/PdO-2
exhibits
optimum
sensitivity,
with
response
value
5.56
100
160
°C
lower
detection
limit
0.75
ppm.
Particularly,
it
has
clear
quantitative
to
actual
liver
kidney
patients.
By
elucidating
intrinsic
link
between
MOF
templates
sensing
mechanism,
is
expected
broaden
rational
design
metal-oxide
thus
provide
an
effective
method
clinical
detection.
Physica Scripta,
Journal Year:
2024,
Volume and Issue:
99(8), P. 085977 - 085977
Published: July 23, 2024
Abstract
In
this
work,
we
report
the
fabrication
and
gas
sensing
application
of
undoped,
Ce
doped
(1,
2,
3,
4,
5
wt%)
MoO
3
thin
films
via
simple,
effective,
low-cost
nebulizer
spray
pyrolysis
method.
The
crystal
structure
prepared
was
found
to
be
monoclinic
by
prominent
peaks
observed
at
(001),
(002)
planes
primary
peak
intensities
increases
from
undoped
3%
film.
morphology
samples
studied
FESEM,
have
nanofibrous
network
embedded
with
nanorods
spread
over
surface
nanofibers.
optical
properties
were
characterised
UV–vis
spectroscopy
that
film’s
energy
band
gap
declines
3.28
3.04
eV
due
dopant
which
alters
levels
conduction
valence
bands
host
oxygen
defects.
defects
analysed
PL
spectroscopy,
it
proved
emission
arose
deficiencies.
produced
higher
intensity
indicated
sites
are
cause.
responses
measured
for
pristine
1,
4
wt%
sensors
increase
6.48
×
10
2
1.67
sensor
detect
ammonia
gas.
significant
property
such
as
rise
time
fall
least
film
54
s.
This
study
revealed
could
an
efficient
room
temperature
in
future.
Surface
modification
with
noble
metal
is
considered
as
an
effective
strategy
to
enhance
sensing
performance
of
semiconductor
gas
sensors.
In
this
work,
gold
nanoparticles
(Au
NPs)
decorated
Gallium
Nitride
nanoflowers
(Au-GaN
NFs)
have
been
synthesized
successfully
by
a
feasible
hydrothermal
method
combined
high
temperature
nitridation
and
followed
in-situ
reduction
process.
The
characterizations
the
structure
morphology
as-obtained
Au-GaN
NFs
indicated
that
Au
NPs
were
loaded
on
surface
GaN.
excellent
was
observed
for
GaN
2
mol%
loaded,
including
response
(86.8%)
100
ppm
NH3
fast
response/recovery
time
(41
s/169
s)
at
room
temperature,
low
theoretical
limit
detection
(72
ppb),
good
stability
selectivity.
Besides,
influence
humidity
sensors
explored,
where
can
be
reached
56.5%
towards
under
70%
RH.
improvement
sensor
attributed
action
chemical
electronic
sensitization
NPs.
This
work
provides
candidate
development
wireless
system
in
monitoring.
Real-time
monitoring
of
toxic
gases
can
be
performed
by
metal
oxide
semiconductor-based
chemo-resistive
gas
sensors
due
to
their
simple
structures,
low
cost,
and
faster
better
recovery
response.
Due
the
effective
electron-hole
separation,
tuning
formation
phase
junctions
is
an
efficient
method
for
improving
sensing
properties.
In
this
study,
two
distinct
hydrothermal
methods
were
used
synthesize
h-/m-WO3
hetero-nanoflowers.
first
method,
L-Cysteine
was
facilitate
between
h-WO3
m-WO3
nanostructures,
whereas
Thiourea
in
second.
Various
characterisation
approaches
validated
hexagonal-monoclinic
junction
development
nanoflowers.
The
material
fabricated
using
with
a
concentration
0.01M
than
other
sensors.
At
350°C,
selected
sample
displayed
outstanding
ammonia
capacity
experimental
detection
limit
1
ppm
(response=3.33).
theoretical
determined
27
ppb.
selectivity
sensor
towards
NH3
over
H2S
acetone
increased
combining
devices
double
filtration
setup.
