H2S selective sensitivity of Cu doped BaSrTiO3 under operando conditions and the associated sensing mechanism

H2S selective sensitivity of Cu doped BaSrTiO3 under operando conditions and the associated sensing mechanism

Publication Type:

Journal Article

Source:

Sensors and Actuators B-Chemical, Volume 264, p.327-336 (2018)

ISBN:

0925-4005

Abstract:

<p>Nanostructured Cu mol. 5% doped perovskite material Ba0.75Sr0.25TiO3 was synthesized under hydrothermal conditions and further on deposited via RF sputtering technique onto commercial Al2O3 substrates provided with Au interdigital electrodes and Pt heater. The obtained thin films have been analyzed by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM), X-ray photoelectron spectroscopy (XPS), Differential Scanning Calorimetry-Thermogravimetry (DSC-TG) and electrical investigations. The H2S (5-90 ppm) gas-surface interaction at moderate operating temperature (T-op = 250 degrees C) associated with the interplay between the pre-adsorbed oxygen species and surface dipolar hydroxyl groups, has been highlighted by simultaneous work function and electrical resistance measurements. By correlation with the XPS spectra, the dominant role of surface hydroxylation was revealed and the subsequent gas sensing mechanism under operando conditions has been addressed. (C) 2018 Elsevier B.V. All rights reserved.</p>