Effects of Ag Additive in Low Temperature CO Detection with In2O3 Based Gas Sensors

Nanomaterials

Alexander Baranchikov¹  Marina Rumyantseva¹  Darya Filatova¹  Alexander Gaskov¹  Joke Hadermann²  Maria Batuk²  Daniil Naberezhnyi³  Elizaveta Konstantinova⁴  Anatoly Aksenenko⁵  Nikolay Khmelevsky⁵ 

[1] Chemistry Department, Moscow State University, Moscow 119991, Russia;EMAT, University of Antwerp, B-2020 Antwerp, Belgium;Faculty of Materials Science, Moscow State University, Moscow 119991, Russia;Faculty of Physics, Moscow State University, Moscow 119991, Russia;LISM, Moscow State Technological University Stankin, Moscow 127055, Russia;

关键词: nanocrystalline semiconductor oxides;    nanocomposites;    indium oxide;    silver additive;    carbon monoxide;    gas sensor;    surface hydroxyl groups;    room temperature response;   

DOI  :  10.3390/nano8100801

来源: DOAJ

【 摘 要 】

Nanocomposites In2O3/Ag obtained by ultraviolet (UV) photoreduction and impregnation methods were studied as materials for CO sensors operating in the temperature range 25–250 °C. Nanocrystalline In2O3 and In2O3/Ag nanocomposites were characterized by X-ray diffraction (XRD), single-point Brunauer-Emmet-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with energy dispersive X-ray (EDX) mapping. The active surface sites were investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy and thermo-programmed reduction with hydrogen (TPR-H2) method. Sensor measurements in the presence of 15 ppm CO demonstrated that UV treatment leads to a complete loss of In2O3 sensor sensitivity, while In2O3/Ag-UV nanocomposite synthesized by UV photoreduction demonstrates an increased sensor signal to CO at T < 200 °C. The observed high sensor response of the In2O3/Ag-UV nanocomposite at room temperature may be due to the realization of an additional mechanism of CO oxidation with participation of surface hydroxyl groups associated via hydrogen bonds.

【 授权许可】

Unknown