TY - JOUR
T1 - Porous, 3D-hierarchical α-NiMoO4 rectangular nanosheets for selective conductometric ethanol gas sensors
AU - Sharma, Bharat
AU - Karuppasamy, K.
AU - Vikraman, Dhanasekaran
AU - Jo, Eun Bee
AU - Sivakumar, P.
AU - Kim, Hyun Seok
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/11/15
Y1 - 2021/11/15
N2 - Transition metal oxides with unique nanoarchitectures are being appraised as plausible candidates for the highly selective detection of contaminating organic gases due to their earth abundance, high surface area, and outstanding miniaturization potential. Here, two different nanoarchitectures of nickel molybdate (NMO), namely 3D-honeycombs (NMO-HCs) and 3D-rectangular nanosheets (NMO-RNS), are proposed and synthesized via a two-step wet-chemical process and characterized for their potential application in ethanol gas sensors. The successful formation of the different nanostructures and the even distribution of all the elements are demonstrated using various morphological and energy-dispersive X-ray spectroscopic (EDAX) analyses. In addition, N2-adsorption/desorption analysis is performed to confirm the highly porous nature and maximum surface areas of 30.4 m2 g−1 and 91.3 m2 g−1 at 77 K for the NMO-HCs and NMO-RNS, respectively. Furthermore, gas sensing analysis reveals that the NMO-HCs-based sensor provides a maximum gas response (Ra/Rg) of ~15.2 while the NMO-RNS-based sensor exhibits a 5.5 times higher maximum gas response of ~78.9 at the optimal operating temperature. Further, using Ra/Rg = 1.2 as the detection limit point, the lower limit of ethanol gas detection is found to be 0.2 ppm for the NMO-RNS-based device. Finally, the probable gas-sensing mechanism of the NMO-RNS is discussed. The present study indicates that the NMO-RNS sensor can sense ppb-levels of ethanol and is suitable for the monitoring of outdoor and indoor air quality in practical applications.
AB - Transition metal oxides with unique nanoarchitectures are being appraised as plausible candidates for the highly selective detection of contaminating organic gases due to their earth abundance, high surface area, and outstanding miniaturization potential. Here, two different nanoarchitectures of nickel molybdate (NMO), namely 3D-honeycombs (NMO-HCs) and 3D-rectangular nanosheets (NMO-RNS), are proposed and synthesized via a two-step wet-chemical process and characterized for their potential application in ethanol gas sensors. The successful formation of the different nanostructures and the even distribution of all the elements are demonstrated using various morphological and energy-dispersive X-ray spectroscopic (EDAX) analyses. In addition, N2-adsorption/desorption analysis is performed to confirm the highly porous nature and maximum surface areas of 30.4 m2 g−1 and 91.3 m2 g−1 at 77 K for the NMO-HCs and NMO-RNS, respectively. Furthermore, gas sensing analysis reveals that the NMO-HCs-based sensor provides a maximum gas response (Ra/Rg) of ~15.2 while the NMO-RNS-based sensor exhibits a 5.5 times higher maximum gas response of ~78.9 at the optimal operating temperature. Further, using Ra/Rg = 1.2 as the detection limit point, the lower limit of ethanol gas detection is found to be 0.2 ppm for the NMO-RNS-based device. Finally, the probable gas-sensing mechanism of the NMO-RNS is discussed. The present study indicates that the NMO-RNS sensor can sense ppb-levels of ethanol and is suitable for the monitoring of outdoor and indoor air quality in practical applications.
KW - Ethanol gas sensors
KW - Mesopores
KW - Nanosheets
KW - NMO-RNS
KW - Wet chemical process
KW - α-NiMoO
UR - http://www.scopus.com/inward/record.url?scp=85113628948&partnerID=8YFLogxK
U2 - 10.1016/j.snb.2021.130615
DO - 10.1016/j.snb.2021.130615
M3 - Article
AN - SCOPUS:85113628948
SN - 0925-4005
VL - 347
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
M1 - 130615
ER -