Surface defect and gas-sensing performance of the well-aligned
Sm-doped SnO
2
nanoarrays
Yanping Zhao
a,1
, Yuehua Li
b,1
, Wenjing Wan
a
, Xingping Ren
c,
⇑
, Heyun Zhao
a,
⇑
a
College of Materials Science and Engineering, Yunnan University, Kunming 650091, PR China
b
Advanced Measurement Center of Dali University, Dali 671200, PR China
c
Yunnan Security and Technology Co. Ltd., Kunming 650033, PR China
article info
Article history:
Received 6 December 2017
Received in revised form 17 January 2018
Accepted 25 January 2018
Keywords:
Tin dioxide
Sm dopant
Nanoarrays
Defects
Semiconductors
Sensors
abstract
Well-oriented Sm-doped SnO
2
nanoarrays were synthesized by a one-pot substrate-free hydrothermal
route. The surface defect of the SnO
2
nanorods caused by the Sm ions doped into the SnO
2
lattice was
investigated. The gas-sensing properties indicated that the Sm-doped SnO
2
nanoarrays with optimized
doping level of 1.50 at% exhibited an excellent sensing response toward isopropanol at a lower temper-
ature. The enhancement response of the Sm-doped SnO
2
nanoarrays was discussed.
Ó 2018 Elsevier B.V. All rights reserved.
1. Introduction
Rutile structured SnO
2
, a well-known n-type wide band gap
semiconductor (Eg = 3.6 eV), has gained prominent attention due
to its extensive applications in many fields [1]. Its most important
application is to be used as the sensitive materials for detection of
various VOCs in the field of gas sensors [2]. However, the gas-
sensing performances of SnO
2
sensor have not been satisfactory
about sensitivity, operating temperature and response/recovery
time. Therefore, there is still of great challenge to develop novel
SnO
2
nanomaterials with excellent gas sensing properties.
Because of the ordered arrangement structural features are of
great benefit for the detection of pollutant gases, one-
dimensional (1-D) nanoarray structures of metal oxide have been
attracted widespread attention [3,4]. In addition, attributing to
their fast oxygen ion mobility and catalytic properties, the positive
effects on the gas-sensing properties of rare earth doped SnO
2
nanomaterials have been investigated by various authors [5,6].
Although seldom research works also have been presented that
doping Sm can enhance the sensing properties [7,8], no attention
has already been focused on the fabrication of Sm-doped SnO
2
well-aligned nanorarrays and their gas sensitivity properties.
Herein, pristine and different atomic ratios of Sm-doped well-
aligned layered SnO
2
nanoarrays were successfully synthesized
using a substrate-free hydrothermal route. The gas sensing exper-
iments of Sm-doped SnO
2
towards isopropanol were carried out
compared with the pristine SnO
2
nanoarrays to envisage the effect
of Sm-doped on the high gas-sensing performance of sensors.
2. Experimental
Sm-doped SnO
2
layered nanoarrays were synthesized via a sim-
ple hydrothermal route without any surfactants and in the absence
of substrates, which was an improved scheme described in our pre-
vious report [9]. Briefly, 7.5 mmol Na
2
SnO
3
4H
2
O and suitable
NaOH were dissolved in 40 ml deionized water with continuously
stirring for 30 min. Then, 40 ml absolute ethanol was slowly added
into the mixed solution to form white suspension aqueous/ethanol
mixed solution stirring for 60 min. The mixed solution was trans-
ferred into a 100 ml Teflon-lined stainless steel autoclave and
maintained at 190 °C for 48 h. After that, the collected precipitates
were washed several times with distilled water and absolute etha-
nol, and then dried at 80 °C in air to get the final products. For the
acquisition of the Sm-doped SnO
2
nanoarrays with different Sm
doping ratio, a suitable content of samarium chloride was added
to the precursor solution with Sm to Sn atomic ratio of 0 at%, 0.5
at%, 1 at% and 1.5 at%, respectively.
https://doi.org/10.1016/j.matlet.2018.01.136
0167-577X/Ó 2018 Elsevier B.V. All rights reserved.
⇑
Corresponding authors.
E-mail addresses: rxp89@126.com (X. Ren), hyzhao@ynu.edu.cn (H. Zhao).
1
Yuehua Li and Yanping Zhao contributed equally to this work.
Materials Letters 218 (2018) 22–26
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