High optical response NiO, Pd/NiO and Pd/WO3 hydrogen sensors
Küçük Resim Yok
Tarih
2022
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Pergamon-Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, NiO and WO3 oxide semiconductors were fabricated on glass substrates by RF Magnetron Sputtering technique. Structural and optical characterizations of the semiconductors were performed using XRD, SEM, and optical absorption measurements. NiO and WO3 thin films were occasionally coated with palladium. In order to investigate the optical response of these semiconductors under hydrogen gas exposure, an optical gas sensor test system was installed and programmed. In both of the coated and uncoated cases, optical absorption changes due to hydrogen gas exposure on the surface were investigated. It was observed that these changes occur between 450 and 850 nm wave lengths range. The absorption in the NiO semiconductor was reduced between these wave lengths, while the absorption was increased in the WO3 semiconductor. In the uncoated state, only NiO gave an optical response to hydrogen gas. While the palladium coated NiO (Pd/NiO) sensor had the best response and recovery times of respectively 70 s and 206 s for 2% fraction of H-2 gas at 300 degrees C constant temperature, the Pd/WO3 sensor gave the best response time of 340 s. Palladium coating resulted in approximately 150% increase in the responses of the NiO sensors at higher H-2 concentration. The lower limit of H-2 sensing of the Pd/NiO sensors at 300 degrees C was at the H-2 fraction of 0.05%, while for Pd/WO3 sensors this value was 0.025%. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Gas sensors, Hydrogen sensors, Optical response, Surface energy
Kaynak
International Journal of Hydrogen Energy
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
47
Sayı
60
