Chemiresistors Based on Li-Doped CuO-TiO2 Films

0546331 - ÚJF 2022 RIV CH eng J - Journal Article
Torrisi, Alfio - Vacík, Jiří - Ceccio, Giovanni - Cannavó, Antonino - Lavrentiev, Vasyl - Horák, Pavel - Yatskiv, Roman - Vaniš, Jan - Grym, Jan - Fišer, L. - Hruška, M. - Otta, J. - Vrňata, M. - Fitl, P.
Chemiresistors Based on Li-Doped CuO-TiO2 Films.
Chemosensors. Roč. 9, č. 9 (2021), č. článku 246. E-ISSN 2227-9040
R&D Projects: GA ČR GA19-02804S
Research Infrastructure: CANAM II - 90056; Reactors LVR-15 and LR-0 II - 90120
Institutional support: RVO:67985882 ; RVO:61389005
Keywords : chemiresistor * CuO-TiO2 heterojunction * Li-doping
OECD category: Nuclear physics; Electrical and electronic engineering (URE-Y)
Impact factor: 4.229, year: 2021
Method of publishing: Open access
https://doi.org/10.3390/chemosensors9090246

Chemiresistors based on thin films of the Li-doped CuO-TiO2 heterojunctions were synthesized by a 2-step method: (i) repeated ion beam sputtering of the building elements (on the Si substrates and multisensor platforms), and (ii) thermal annealing in flowing air. The structure and composition of the films were analyzed by several methods: Rutherford Backscattering (RBS), Neutron Depth Profiling (NDP), Secondary Ion Mass Spectrometry (SIMS), and Atomic Force Microscopy (AFM), and their sensitivity to gaseous analytes was evaluated using a specific lab-made device operating in a continuous gas flow mode. The obtained results showed that the Li doping significantly increased the sensitivity of the sensors to oxidizing gases, such as NO2, O-3, and Cl-2, but not to reducing H-2. The sensing response of the CuO-TiO2-Li chemiresistors improved with increasing Li content. For the best sensors with about 15% Li atoms, the detection limits were as follows: NO2 -> 0.5 ppm, O-3 -> 10 ppb, and Cl-2 -> 0.1 ppm. The Li-doped sensors showed excellent sensing performance at a lower operating temperature (200 degrees C). However, even though their response time was only a few minutes, their recovery was slow (up to a few hours) and incomplete.
Permanent Link: http://hdl.handle.net/11104/0322868