Sensitive Room-Temperature H2S Gas Sensors Employing SnO2 ...
Supporting Information
Sensitive Room-Temperature H2S Gas Sensors Employing SnO2 Quantum Wire/Reduced Graphene Oxide Nanocomposites Zhilong Song, Zeru Wei, Baocun Wang, Zhen Luo, Songman Xu, Wenkai Zhang, Haoxiong Yu, Min Li, Zhao Huang, Jianfeng Zang, Fei Yi, Huan Liu* School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, People’ s Republic of China Email: [email protected].
a)
b)
c)
d)
e)
f)
Figure S1 The diameter distributions of the (a, c, e) pristine SnO2 and (b, d, f) SnO2/rGO nanocomposites synthesized at 180 °C for 3 h (panels a and b), 6 h (panels c and d), and 8 h (panels e and f).
a)
b)
Figure S2 a) Room-temperature response curves of the gas sensors based on SnO2/rGO (8 h) nanocomposites before (black) and after ligand treatment, b) XPS spectra of SnO2/rGO nanocomposites (8 h) after Cu(NO3)2 treatment (Cu 2p).
Figure S3 Response time vs. H2S gas concentration (10, 20, 40, 50, 60, 80, 100 ppm) curve of the gas sensors based on SnO2/ rGO nanocomposites (8 h) at 22 oC.
Figure S4 The response curve of the gas sensors based on SnO2/rGO nanocomposites (8 h) toward ppb-level H2S gas at 22oC: 100 ppb and 43 ppb (LOD).
Samples
rGO/SnO2 ratio
Ra (MΩ)
S (Ra/Rg)
T90/T10 (s)
SnO2/rGO (8 h)-1
1.94 wt%
221
23.4
23/220
SnO2/rGO (8 h)-2
3.88 wt%
148
33.4
4/210
SnO2/rGO (8 h)-3
38.8 wt%
61
25.3
3/83
Figure S5 Response curves toward 50 ppm H2S at room temperature based on SnO2/rGO nanocomposites (8 h) with different amount of rGO, respectively.
Figure S6 Work functions of a) SnO2 quantum wires (4.53 eV) and b) rGO nanosheets (4.74 eV) measured by Kelvin probe based on 20 data points.
a)
b)
Figure S7 Sn 3d (a) and O1s (b) XPS spectra of SnO2 (8 h) and SnO2/rGO nanocomposites (8 h) after Cu(NO3)2 treatment , respectively.
Figure S8 SEM images of the gas sensors based on a) the pristine SnO2 quantum wires (8 h) and b) the SnO2/rGO nanocomposites (8 h), respectively.
Sensitive Room-Temperature H2S Gas Sensors Employing SnO2 Quantum Wire/Reduced Graphene Oxide Nanocomposites Zhilong Song, Zeru Wei, Baocun Wang, Zhen Luo, Songman Xu, Wenkai Zhang, Haoxiong Yu, Min Li, Zhao Huang, Jianfeng Zang, Fei Yi, Huan Liu* School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074, People’ s Republic of China Email: [email protected].
a)
b)
c)
d)
e)
f)
Figure S1 The diameter distributions of the (a, c, e) pristine SnO2 and (b, d, f) SnO2/rGO nanocomposites synthesized at 180 °C for 3 h (panels a and b), 6 h (panels c and d), and 8 h (panels e and f).
a)
b)
Figure S2 a) Room-temperature response curves of the gas sensors based on SnO2/rGO (8 h) nanocomposites before (black) and after ligand treatment, b) XPS spectra of SnO2/rGO nanocomposites (8 h) after Cu(NO3)2 treatment (Cu 2p).
Figure S3 Response time vs. H2S gas concentration (10, 20, 40, 50, 60, 80, 100 ppm) curve of the gas sensors based on SnO2/ rGO nanocomposites (8 h) at 22 oC.
Figure S4 The response curve of the gas sensors based on SnO2/rGO nanocomposites (8 h) toward ppb-level H2S gas at 22oC: 100 ppb and 43 ppb (LOD).
Samples
rGO/SnO2 ratio
Ra (MΩ)
S (Ra/Rg)
T90/T10 (s)
SnO2/rGO (8 h)-1
1.94 wt%
221
23.4
23/220
SnO2/rGO (8 h)-2
3.88 wt%
148
33.4
4/210
SnO2/rGO (8 h)-3
38.8 wt%
61
25.3
3/83
Figure S5 Response curves toward 50 ppm H2S at room temperature based on SnO2/rGO nanocomposites (8 h) with different amount of rGO, respectively.
Figure S6 Work functions of a) SnO2 quantum wires (4.53 eV) and b) rGO nanosheets (4.74 eV) measured by Kelvin probe based on 20 data points.
a)
b)
Figure S7 Sn 3d (a) and O1s (b) XPS spectra of SnO2 (8 h) and SnO2/rGO nanocomposites (8 h) after Cu(NO3)2 treatment , respectively.
Figure S8 SEM images of the gas sensors based on a) the pristine SnO2 quantum wires (8 h) and b) the SnO2/rGO nanocomposites (8 h), respectively.
