Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals
Monolayer, bilayer, and trilayer graphene quantum dots (GQDs) with different binding abilities to elemental heavy metals (HMs: Cd, Hg, and Pb) were designed, and their electronic and optical properties were investigated theoretically to understand deeply the optical response under heavy metal exposu...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-07-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1996-1944/11/7/1217 |
| _version_ | 1811307123928203264 |
|---|---|
| author | Ivan Shtepliuk Rositsa Yakimova |
| author_facet | Ivan Shtepliuk Rositsa Yakimova |
| author_sort | Ivan Shtepliuk |
| collection | DOAJ |
| description | Monolayer, bilayer, and trilayer graphene quantum dots (GQDs) with different binding abilities to elemental heavy metals (HMs: Cd, Hg, and Pb) were designed, and their electronic and optical properties were investigated theoretically to understand deeply the optical response under heavy metal exposure. To gain insight into the nature of interband absorption, we performed density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations for thickness-varying GQDs. We found that the interband absorption in GQDs can be efficiently tuned by controlling the thickness of GQDs to attain the desirable coloration of the interacting complex. We also show that the strength of the interaction between GQDs and Cd, Hg, and Pb is strongly dependent on the number of sp2-bonded layers. The results suggest that the thickness of GQDs plays an important role in governing the hybridization between locally-excited (LE) and charge-transfer (CT) states of the GQDs. Based on the partial density-of-states (DOS) analysis and in-depth knowledge of excited states, the mechanisms underlying the interband absorption are discussed. This study suggests that GQDs would show an improved sensing performance in the selective colorimetric detection of lead by the thickness control. |
| first_indexed | 2024-04-13T08:58:14Z |
| format | Article |
| id | doaj.art-82b217d83ef24733a86eece442290c9f |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-04-13T08:58:14Z |
| publishDate | 2018-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-82b217d83ef24733a86eece442290c9f2022-12-22T02:53:14ZengMDPI AGMaterials1996-19442018-07-01117121710.3390/ma11071217ma11071217Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy MetalsIvan Shtepliuk0Rositsa Yakimova1Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, SwedenDepartment of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, SwedenMonolayer, bilayer, and trilayer graphene quantum dots (GQDs) with different binding abilities to elemental heavy metals (HMs: Cd, Hg, and Pb) were designed, and their electronic and optical properties were investigated theoretically to understand deeply the optical response under heavy metal exposure. To gain insight into the nature of interband absorption, we performed density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations for thickness-varying GQDs. We found that the interband absorption in GQDs can be efficiently tuned by controlling the thickness of GQDs to attain the desirable coloration of the interacting complex. We also show that the strength of the interaction between GQDs and Cd, Hg, and Pb is strongly dependent on the number of sp2-bonded layers. The results suggest that the thickness of GQDs plays an important role in governing the hybridization between locally-excited (LE) and charge-transfer (CT) states of the GQDs. Based on the partial density-of-states (DOS) analysis and in-depth knowledge of excited states, the mechanisms underlying the interband absorption are discussed. This study suggests that GQDs would show an improved sensing performance in the selective colorimetric detection of lead by the thickness control.http://www.mdpi.com/1996-1944/11/7/1217DFTfew-layer graphene quantum dotsheavy metalsinteractionabsorption spectroscopyDOS |
| spellingShingle | Ivan Shtepliuk Rositsa Yakimova Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals Materials DFT few-layer graphene quantum dots heavy metals interaction absorption spectroscopy DOS |
| title | Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals |
| title_full | Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals |
| title_fullStr | Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals |
| title_full_unstemmed | Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals |
| title_short | Interband Absorption in Few-Layer Graphene Quantum Dots: Effect of Heavy Metals |
| title_sort | interband absorption in few layer graphene quantum dots effect of heavy metals |
| topic | DFT few-layer graphene quantum dots heavy metals interaction absorption spectroscopy DOS |
| url | http://www.mdpi.com/1996-1944/11/7/1217 |
| work_keys_str_mv | AT ivanshtepliuk interbandabsorptioninfewlayergraphenequantumdotseffectofheavymetals AT rositsayakimova interbandabsorptioninfewlayergraphenequantumdotseffectofheavymetals |