Open AccessVisible Light-Induced Room-Temperature Formaldehyde Gas Sensor Based on Porous Three-Dimensional ZnO Nanorod Clusters with Rich Oxygen Vacancies
Author(s) -
Bo Zhang,
Jing Wang,
Qufu Wei,
Pingping Yu,
Shuai Zhang,
Yin Xu,
Yue Dong,
Yi Ni,
Jinping Ao,
Yi Xia
Publication year - 2022
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.2c02613
Subject(s) - materials science , nanorod , x ray photoelectron spectroscopy , photoluminescence , absorption (acoustics) , oxygen , semiconductor , band gap , visible spectrum , absorption spectroscopy , nanotechnology , chemical engineering , optoelectronics , chemistry , optics , composite material , organic chemistry , engineering , physics
Oxygen vacancy (V O ) is a kind of primary point defect that extensively exists in semiconductor metal oxides (SMOs). Owing to some of its inherent qualities, an artificial manipulation of V O content in one material has evolved into a hot research field, which is deemed to be capable of modulating band structures and surface characteristics of SMOs. Specific to the gas-sensing area, V O engineering of sensing materials has become an effective means in enhancing sensor response and inducing light-enhanced sensing. In this work, a high-efficiency microwave hydrothermal treatment was utilized to prepare a V O -rich ZnO sample without additional reagents. The X-ray photoelectron spectroscopy test revealed a significant increase in V O proportion, which was from 9.21% in commercial ZnO to 36.27% in synthesized V O -rich ZnO possessing three-dimensional and air-permeable microstructures. The subsequent UV-vis-NIR absorption and photoluminescence spectroscopy indicated an extension absorption in the visible region and band gap reduction of V O -rich ZnO. It turned out that the V O -rich ZnO-based sensor exhibited a considerable response of 63% toward 1 ppm HCHO at room temperature (RT, 25 °C) under visible light irradiation. Particularly, the response/recovery time was only 32/20 s for 1 ppm HCHO and further shortened to 10/5 s for 10 ppm HCHO, which was an excellent performance and comparable to most sensors working at high temperatures. The results in this work strongly suggested the availability of V O engineering and also provided a meaningful candidate for researchers to develop high-performance RT sensors detecting volatile organic compounds.