Ultraviolet light-emitting diode-assisted highly sensitive room temperature NO2 gas sensors based on low-temperature solution-processed ZnO/TiO2 nanorods decorated with plasmonic Au nanoparticles

Soon-Hwan Kwon; Tae-Hyeon Kim; Sang-Min Kim; Semi Oh; Kyoung-Kook Kim

doi:10.1039/d1nr01001h

Ultraviolet light-emitting diode-assisted highly sensitive room temperature NO₂ gas sensors based on low-temperature solution-processed ZnO/TiO₂ nanorods decorated with plasmonic Au nanoparticles

Nanoscale. 2021 Jul 28;13(28):12177-12184. doi: 10.1039/d1nr01001h. Epub 2021 Jul 14.

Authors

Soon-Hwan Kwon¹, Tae-Hyeon Kim, Sang-Min Kim, Semi Oh, Kyoung-Kook Kim

Affiliation

¹ Department of Advanced Convergence Technology, Korea Polytechnic University, 237 Sangidaehak-ro, Siheung-si, Geyonggi-do 15073, Republic of Korea. kim.kk@kpu.ac.kr.

PMID: 34259295
DOI: 10.1039/d1nr01001h

Abstract

Nanostructured semiconducting metal oxides such as SnO₂, ZnO, TiO₂, and CuO have been widely used to fabricate high performance gas sensors. To improve the sensitivity and stability of gas sensors, we developed NO₂ gas sensors composed of ZnO/TiO₂ core-shell nanorods (NRs) decorated with Au nanoparticles (NPs) synthesized via a simple low-temperature aqueous solution process, operated under ultraviolet irradiation to realize room temperature operation. The fabricated gas sensor with a 10 nm-thick TiO₂ shell layer shows 9 times higher gas sensitivity and faster response and recovery times than ZnO NR-based gas sensors. This high performance of the fabricated gas sensor can be ascribed to band bending between the ZnO and TiO₂ core-shell layers and the localized surface plasmon resonance effect of Au NPs with a sufficient Debye length of the TiO₂ shell layer.