NAP-XPS Study of Ethanol Adsorption on TiO2 Surfaces and Its Impact on Microwave-Based Gas
نویسندگان
چکیده
This work presents new elements of understanding for the microwave-based gas sensors behavior at room temperature. A TiO2-covered microstrip interdigital capacitor was submitted to various ethanol concentrations and showed a proportional response in the 1–10 GHz microwave range. For each concentration and right after ethanol injection, the sensor response presented a slight overshoot which is often found in gas sensors studies. Near ambient pressure photoemission experiments (NAP-XPS) were conducted to explore the physicochemical causes of this overshoot, and demonstrated the formation of an ethoxide during ethanol adsorption.
منابع مشابه
A high-pressure-induced dense CO overlayer on a Pt(111) surface: a chemical analysis using in situ near ambient pressure XPS.
We investigated the high-density CO adsorption phase formed on a Pt(111) surface when exposed to CO gas of pressure ranging from UHV to 100 mTorr using near-ambient-pressure (NAP)-XPS. Combined results from the NAP-XPS measurements and DFT calculations reveal the adsorption structure of CO molecules in the dense CO overlayer, which is stable under realistic conditions.
متن کاملWater adsorption on TiO2 surfaces probed by soft X-ray spectroscopies: bulk materials vs. isolated nanoparticles
We describe an experimental method to probe the adsorption of water at the surface of isolated, substrate-free TiO2 nanoparticles (NPs) based on soft X-ray spectroscopy in the gas phase using synchrotron radiation. To understand the interfacial properties between water and TiO2 surface, a water shell was adsorbed at the surface of TiO2 NPs. We used two different ways to control the hydration le...
متن کاملNon-Dissociative Gas Adsorption with Different Chemisorption Geometries on Nanoporous Surfaces
Isotherm equation is one of the important scientific bases for adsorbent selection. There are different isotherms that do not account for an adsorbate, different chemisorption geometries on the nanoporous surface. It is interesting to introduce a general isotherm, which considers different chemisorption geometries of an adsorbate on nanoporous surfaces. In this study, an isotherm for non-dissoci...
متن کاملHighly Sensitive Detection of H2S Molecules Using a TiO2-Supported Au Overlayer Based Nanosensors: A Van Der Waals Corrected DFT Study
The adsorption of the H2S molecule on the undoped and N-doped TiO2 anatase supported Au nanoparticles were studied using density functional theory calculations. The adsorption of H2S on both Au and TiO2 sides of the nanoparticle was examined. On the TiO2 side, the fivefold coordinated titanium site was found to be the most favorable binding site, giving rise to the strong interaction of H2S wit...
متن کاملTiO2/Graphene oxide nanocomposite as an ideal NO gas sensor: A density functional theory study
We performed a density functional theory investigation on the structural and electronic properties of pristine and nitrogen-doped TiO2/Graphene oxide nanocomposites as the adsorbents for the removal of toxic NO molecules in the environment. We presented the most stable adsorption configurations and examined the interaction of NO molecule with these doped and undoped nanocomposites. It turns out...
متن کامل