High-performance UV-activated room temperature NO2 sensors based on TiO2/In2O3 composite

Zhicheng Cai; Jiho Park; Doyeon Jun; Sunghoon Park

doi:10.1039/D3CE00004D

High-performance UV-activated room temperature NO₂ sensors based on TiO₂/In₂O₃ composite†

Zhicheng Cai,

^a Jiho Park,^b Doyeon Jun^c and Sunghoon Park

*^cd

Author affiliations

* Corresponding authors

^a Department of Software Convergence, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, South Korea

^b Department of Electronics and Information Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, South Korea

^c Department of Intelligent and Mechatronics Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, South Korea
E-mail: s.park@sejong.ac.kr

^d Department of Semiconductor System Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, South Korea

Abstract

Porous TiO₂ nanoparticle (NPs)-embedded In₂O₃ nanofibers (NFs) were synthesized using electrospinning for fabricating room temperature (RT) nitrogen dioxide (NO₂) gas sensors. The diameter of the porous polycrystalline TiO₂/In₂O₃ nanofibers was 60 nm and they were composed of sub-grains of average size 10–15 nm. Compared to pure In₂O₃ nanofibers, the TiO₂/In₂O₃ nanofibers exhibited higher response, shorter response and recovery times, better reproducibility, and improved selectivity to NO₂. The response of the TiO₂/In₂O₃ composite to 5 ppm NO₂ at RT under ultraviolet (UV) irradiation was 49.29, which was 8.96 times higher than that of pure In₂O₃. Even for a high relative humidity (RH) of 80%, the response of the TiO₂/In₂O₃ composite to 5 ppm NO₂ was approximately 41.25. The enhanced NO₂ sensing performance of the composite can be ascribed to the formation of the TiO₂/In₂O₃ n–n heterojunction, porous structure of the nanofibers, enhanced light absorption, and large number of O vacancies.

This article is part of the themed collection: Editor’s Collection: Advances in nanocrystal heterojunctions

Supplementary files

Article information

DOI: https://doi.org/10.1039/D3CE00004D
Article type: Paper
Submitted: 02 jan 2023
Accepted: 07 mar 2023
First published: 29 mar 2023

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CrystEngComm, 2023,25, 2546-2556

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High-performance UV-activated room temperature NO₂ sensors based on TiO₂/In₂O₃ composite

Z. Cai, J. Park, D. Jun and S. Park, CrystEngComm, 2023, 25, 2546 DOI: 10.1039/D3CE00004D

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