Citation: Liu, X.; Li, J.; Guo, L.; Wang,
G. Highly Sensitive Acetone Gas
Sensors Based on Erbium-Doped
Bismuth Ferrite Nanoparticles.
Nanomaterials 2022, 12, 3679.
https://doi.org/10.3390
/nano12203679
Academic Editor: Sergei Kulinich
Received: 31 August 2022
Accepted: 17 October 2022
Published: 20 October 2022
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Article
Highly Sensitive Acetone Gas Sensors Based on Erbium-Doped
Bismuth Ferrite Nanoparticles
Xiaolian Liu *, Jing Li, Lanlan Guo and Guodong Wang *
School of Physics and Electronic Information Engineering, Henan Polytechnic University, Jiaozuo 454003, China
* Correspondence: liuxl123@hpu.edu.cn (X.L.); wgd@hpu.edu.cn (G.W.); Tel.: +86-13290706609 (X.L.)
Abstract:
The acetone-sensing performance of BiFeO
3
is related to structural phase transformation,
morphology and band gap energy which can be modulated by rare-earth ions doping. In this
work, Bi
1−x
Er
x
FeO
3
nanoparticles with different amounts of Er doping were synthesized via the
sol-gel method. The mechanism of Er doping on acetone-sensing performance of Bi
1−x
Er
x
FeO
3
(
x = 0
, 0.05, 0.1 and 0.2) sensors was the focus of the research. The optimal working temperature of
Bi
0.9
Er
0.1
FeO
3
(300
◦
C) was decreased by 60
◦
C compared to BiFeO
3
(360
◦
C). The Bi
0.9
Er
0.1
FeO
3
sample demonstrated the optimal response to 100 ppm acetone (43.2), which was 4.8 times that of pure
BFO at 300
◦
C. The primary reason, which enhances the acetone-sensing performance, could be the
phase transformation induced by Er doping. The lattice distortions induced by phase transformation
are favorable to increasing the carrier concentration and mobility, which will bring more changes to
the hole-accumulation layer. Thus, the acetone-sensing performance of Bi
0.9
Er
0.1
FeO
3
was improved.
Keywords:
bismuth ferrite nanoparticles; Er doping; acetone gas sensor; morphotropic phase boundary
1. Introduction
Acetone is a common volatile organic compound that is widely used in the chemical
industry and laboratories. However, long-term exposure to acetone or excessive inhalation
of acetone causes great damage to the skin, nervous system, and breathing system, which
leads to dermatitis, headache, nausea and coma [
1
]. Thus, the detection of acetone is
highly significant for human health. Meanwhile, the detection of acetone can be used
in the diagnosis of some diseases. For example, in the breath of diabetes patients, the
concentration of acetone is more than twice as much as that of healthy people [
2
]. Compared
to blood tests, acetone gas sensing is quick, easy, and noninvasive. Consequently, great
attention has been paid to the study of acetone gas sensors. Plenty of oxides have been
reported to show acetone-sensing performance, such as ZnO, SnO
2
, Co
3
O
4
, Fe
2
O
3
, WO
3
and so on. Some strategies have been adopted to optimize gas sensing performance, such
as designing nanomaterial with special morphology and structure [
3
,
4
], preparation of
composite materials [
5
], doping with rare-earth and noble-metal ions [
6
,
7
] and decorating
with other nanomaterial [
8
]. However, studies have shown that binary metal oxides
display excellent gas sensing performance, but suffer from high operating temperature and
relatively poor stability [
9
,
10
]. Consequently, the study of the acetone gas sensor based on
ternary oxides has been of great interest to researchers due to the good thermal stability
and easy modulation of sensing performance.
BiFeO
3
(BFO) is a typical ABO
3
perovskite material with a rhombohedral structure
(R3c space group). Studies have been carried out for its applications in magnetoelectric
memory, photovoltaic devices, spintronics devices and photocatalysis [
11
–
14
]. Researchers
also reported the gas sensing performance of BFO to acetone, formaldehyde, oxygen, nitro-
gen dioxide, isopropanol and so on [
15
–
19
]. Xu et al. [
20
] have studied the gas sensing of
BFO nanocrystals to isopropanol. At 240
◦
C, the response to 100 ppm isopropanol is 31 and
the response and recovery time are 6 s and 17 s. Yu et al. [
21
] have prepared a hierarchical
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