Exploring the properties of Ag5–TiO2 interfaces: stable surface polaron formation, UV-Vis optical response, and CO2 photoactivation

<div>In the atomic layer deposition (ALD) of Cobalt (Co) and Ruthenium (Ru) metal using nitrogen plasma, the structure and composition of the post N-plasma NHx terminated (x = 1 or 2) metal surfaces are not well known but are important in the subsequent metal containing pulse. In this paper, we use the low-index (001) and (100) surfaces of Co and Ru as models of the metal polycrystalline thin films. The (001) surface with a hexagonal surface structure is the most stable surface and the (100) surface with a zigzag structure is the least stable surface but has high reactivity. We investigate the stability of NH and NH2 terminations on these surfaces to determine the saturation coverage of NHx on Co and Ru. NH is most stable in the hollow hcp site on (001) surface and the bridge site on the (100) surface, while NH2 prefers the bridge site on both (001) and (100) surfaces. The differential energy is calculated to find the saturation coverage of NH and NH2. We also present results on mixed NH/NH2-terminations. The results are analyzed by thermodynamics using Gibbs free energies (ΔG) to reveal temperature effects on the stability of NH and NH2 terminations. Ultra-high vacuum (UHV) and standard ALD</div><div>operating conditions are considered. Under typical ALD operating conditions we find that the most stable NHx terminated metal surfaces are 1 ML NH on Ru (001) surface (350K-550K), 5/9 ML NH on Co (001) surface (400K-650K) and a mixture of NH and NH2 on both Ru (100) and Co (100) surfaces.</div>

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The Coherent Nonlinear Optical Response and Control of Single Quantum Dots

10.21236/ada437780 ◽

2005 ◽

Author(s):

Duncan G. Steel

Keyword(s):

Quantum Dots ◽

Nonlinear Optical ◽

Optical Response ◽

Nonlinear Optical Response ◽

Single Quantum ◽

Single Quantum Dots ◽

And Control

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A New Fluorescent Salen-uranyl Sensor for the Sub-ppm Detection of Chemical Warfare Agents

Current Organic Chemistry ◽

10.2174/1385272824999200930150313 ◽

2020 ◽

Vol 24 (20) ◽

pp. 2378-2382

Author(s):

Andrea Pappalardo ◽

Chiara M.A. Gangemi ◽

Rosa Maria Toscano ◽

Giuseppe Trusso Sfrazzetto

Keyword(s):

Real Time ◽

Fluorescent Sensor ◽

Chemical Warfare Agents ◽

Optical Response ◽

Chemical Warfare ◽

Lethal Effects ◽

Strong Affinity ◽

Chemical Attack ◽

Fluorescence Measurements ◽

Warfare Agents

Real-time sensing of Chemical Warfare Agents (CWAs) is today a crucial topic to prevent the lethal effects of a terroristic chemical attack. For this reason, the development of efficient, selective, sensitive and reversible sensoristic devices, able to detect by optical response ppm levels of these compounds, is strongly required. Here, the synthesis of a new fluorescent sensor based on a salen-uranyl scaffold, functionalized with two bodipy moieties, and its application for the detection of sub-ppm levels of CWAs is reported. Detection properties were evaluated by fluorescence measurements and selectivity tests demonstrated the strong affinity for CWAs.

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