Microtubular α-Fe2O3/Fe2(MoO4)3 heterostructure derived from absorbent cotton for enhanced ppb-level H2S gas-sensing performance
•Microtubular α-Fe2O3/Fe2(MoO4)3 heterostructure was simply prepared by using as absorbent cotton biotemplate.•The FFMO sensor possesses the highest sensitivity to 10 ppm H2S rather than reported Fe2(MoO4)3-based sensors.•The response time of 3 s to 10 ppm H2S is the fastest in reported Fe2(MoO4)3-b...
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Published in | Journal of alloys and compounds Vol. 867; p. 158994 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Lausanne
Elsevier B.V
25.06.2021
Elsevier BV |
Subjects | |
Online Access | Get full text |
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Summary: | •Microtubular α-Fe2O3/Fe2(MoO4)3 heterostructure was simply prepared by using as absorbent cotton biotemplate.•The FFMO sensor possesses the highest sensitivity to 10 ppm H2S rather than reported Fe2(MoO4)3-based sensors.•The response time of 3 s to 10 ppm H2S is the fastest in reported Fe2(MoO4)3-based sensors.•The detection limit of 50 ppb is the lowest in reported Fe2(MoO4)3-based sensors.
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Microtubular α-Fe2O3/Fe2(MoO4)3 heterostructure (FFMO) was massively prepared by facile immersion-calcination method with absorbent cotton being employed as template, which is formed by a great number of cross-linking nanoparticles. In comparison with the pure iron molybdate (FMO) microtubules, the small-sized α-Fe2O3 nanocrystals evenly attached to the surface of FMO particles, increasing the specific surface area of FFMO composites and forming broad hierarchical pores. Gas-sensing measurement indicates that the sensor fabricated from FFMO heterostructure presents response of 12.69 toward 10 ppm H2S, being about 2.2 times larger than that of pure FMO-based sensor. And the working temperature also reduces from 170 °C to 133 °C. In particular, the FFMO composite exhibits the fastest response (Tres = 3 s) and the lowest detection limit (50 ppb) to H2S gas among all reported FMO-based sensors. Such rapid response and highly sensitive to trace H2S are dominantly assigned to the synergism of the inherent properties of multistage-pores microtubule, n-n heterojunction, surface adsorbed oxygen, as well as the generation of metastable iron sulfide induced by lattice oxygen. In addition, the gas-sensing mechanism of the sensor is also studied in detail. |
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ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2021.158994 |