The Consequences of Water Interactions with Nitrogen-Containing Carbonaceous Quantum Dots—The Mechanistic Studies
Despite the importance of quantum dots in a wide range of biological, chemical, and physical processes, the structure of the molecular layers surrounding their surface in solution remains unknown. Thus, knowledge about the interaction mechanism of Nitrogen enriched Carbonaceous Quantum Dots’ (N-CQDs...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/23/22/14292 |
| Summary: | Despite the importance of quantum dots in a wide range of biological, chemical, and physical processes, the structure of the molecular layers surrounding their surface in solution remains unknown. Thus, knowledge about the interaction mechanism of Nitrogen enriched Carbonaceous Quantum Dots’ (N-CQDs) surface with water—their natural environment—is highly desirable. A diffusive and Stern layer over the N-CQDs, characterized in situ, reveals the presence of anionic water clusters [OH(H<sub>2</sub>O)<sub>n</sub>]<sup>−</sup>. Their existence explains new observations: (i) the unexpectedly low adsorption enthalpy (ΔH<sub>ads</sub>) in a pressure range below 0.1 p/p<sub>s</sub>, and ΔH<sub>ads</sub> being as high as 190 kJ/mol at 0.11 p/p<sub>s</sub>; (ii) the presence of a “conductive window” isolating nature—at p/p<sub>s</sub> below 0.45—connected to the formation of smaller clusters and increasing conductivity above 0.45 p/p<sub>s</sub>, (iii) Stern layer stability; and (iv) superhydrophilic properties of the tested material. These observables are the consequences of H<sub>2</sub>O dissociative adsorption on N-containing basic centers. The additional direct application of surfaces formed by N-CQDs spraying is the possibility of creating antistatic, antifogging, bio-friendly coatings. |
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| ISSN: | 1661-6596 1422-0067 |