Design of highly sensitive and selective ethanol sensor based on α-Fe2O3/Nb2O5 heterostructure

Rabia Khatoon; Sajid Rauf; Mahmood Ul Haq; Sanam Attique; Salah Ud Din; Nasir Ali; Yichuan Guo; Hongwen Chen; Yang Tian; Jianguo Lu

doi:10.1088/1361-6528/abdd5e

Design of highly sensitive and selective ethanol sensor based on α-Fe₂O₃/Nb₂O₅ heterostructure

Nanotechnology. 2021 May 7;32(19):195503. doi: 10.1088/1361-6528/abdd5e.

Authors

Affiliations

¹ State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
² Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science, Hubei University, Wuhan, Hubei 430062, People's Republic of China.
³ Institute for Composites Science Innovation, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
⁴ Zhejiang Province Key Laboratory of Quantum Technology and Devices and Department of Physics, State Key Laboratory for Silicon Materials, Zhejiang University, Hangzhou, 310027, People's Republic of China.

PMID: 33470969
DOI: 10.1088/1361-6528/abdd5e

Abstract

The introduction of heterostructures is a new approach in gas sensing due to their easy and quick transport of charges. Herein, facile hydrothermal and solid-state techniques are employed to synthesize an α-Fe₂O₃/Nb₂O₅ heterostructure. The morphology, microstructure, crystallinity and surface composition of the synthesized heterostructures are investigated by scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy and Brunauer-Emmett-Teller analyses. The successful fabrication of the heterostructures was achieved via the mutual incorporation of α-Fe₂O₃ nanorods with Nb₂O₅ interconnected nanoparticles (INPs). A sensor based on the α-Fe₂O₃(0.09)/Nb₂O₅ heterostructure with a high surface area exhibited enhanced gas-sensing features, maintaining high selectivity and sensitivity, and a considerable recovery percentage towards ethanol gas. The sensing response of the α-Fe₂O₃(0.09)/Nb₂O₅ heterostructure at lower operating temperature (160 °C) is around nine times higher than a pure Nb₂O₅ (INP) sensor at 180 °C with the flow of 100 ppm ethanol gas. The sensors also show excellent selectivity, good long-term stability and a rapid response/recovery time (8s/2s, respectively) to ethanol. The superior electronic conductivity and upgraded sensitivity performance of gas sensors based on the α-Fe₂O₃(0.09)/Nb₂O₅ heterostructure are attributed due to its unique structural features, high specific surface area and the synergic effect of the n-n heterojunction. The promising results demonstrate the potential application of the α-Fe₂O₃(0.09)/Nb₂O₅ heterostructure as a good sensing material for the fabrication of ethanol sensors.