scholarly journals Size Effect of Graphene Quantum Dots on Photoluminescence

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3922
Author(s):  
Ziyi Liu ◽  
Fei Li ◽  
Yi Luo ◽  
Ming Li ◽  
Guanghui Hu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Hydrothermal Process ◽  
Graphene Quantum Dots ◽  
Density Functional Theory Calculations ◽  
Emission Peak ◽  
One Pot ◽  
Functional Theory ◽  
Molecular Weights

High-photoluminescence (PL) graphene quantum dots (GQDs) were synthesized by a simple one-pot hydrothermal process, then separated by dialysis bags of different molecular weights. Four separated GQDs of varying sizes were obtained and displayed different PL intensities. With the decreasing size of separated GQDs, the intensity of the emission peak becomes much stronger. Finally, the GQDs of the smallest size revealed the most energetic PL intensity in four separated GQDs. The PL energy of all the separated GQDs shifted slightly, supported by density functional theory calculations.

Density functional theory calculations of the radial breathing mode in graphene quantum dots

2019 ◽  
Vol 13 (04) ◽  
pp. 1
Author(s):  
Miguel Ojeda Martínez ◽  
Arturo Nascir Pérez Martínez ◽  
Víctor Manuel Rentería Tapia ◽  
Jose Luis Cuevas Figueroa ◽  
Duncan John Mowbray ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Graphene Quantum Dots ◽  
Density Functional Theory Calculations ◽  
Radial Breathing Mode ◽  
Functional Theory ◽  
Breathing Mode

The optical and electronic properties of graphene quantum dots with oxygen-containing groups: a density functional theory study

2017 ◽  
Vol 5 (24) ◽  
pp. 5984-5993 ◽  
Author(s):  
Jianguang Feng ◽  
Hongzhou Dong ◽  
Liyan Yu ◽  
Lifeng Dong
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Graphene Quantum Dots ◽  
Time Dependent ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
Td Dft ◽  
Dependent Density

The effects of five types of oxygen-containing functional groups (–COOH, –COC–, –OH, –CHO, and –OCH3) on graphene quantum dots (GQDs) are investigated using time-dependent density functional theory (TD-DFT).

Can inorganic salts tune electronic properties of graphene quantum dots?

2015 ◽  
Vol 17 (26) ◽  
pp. 17413-17420 ◽  
Author(s):  
Guilherme Colherinhas ◽  
Eudes Eterno Fileti ◽  
Vitaly V. Chaban
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Graphene Quantum Dots ◽  
Inorganic Salts ◽  
Ionic Clusters ◽  
Functional Theory ◽  
Free Ions

In this work, we apply density functional theory to study the effect of neutral ionic clusters adsorbed on the GQD surface. We conclude that both the HOMO and the LUMO of GQDs are very sensitive to the presence of ions and to their distance from the GQD surface. However, the alteration of the band gap itself is modest, as opposed to the case of free ions (recent reports). Our work fosters progress in modulating electronic properties of nanoscale carbonaceous materials.

Efficient electrocatalytic N2 reduction on CoO quantum dots

2019 ◽  
Vol 7 (9) ◽  
pp. 4389-4394 ◽  
Author(s):  
Ke Chu ◽  
Ya-ping Liu ◽  
Yu-biao Li ◽  
Hu Zhang ◽  
Ye Tian
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Faradaic Efficiency

Density functional theory calculations revealed that CoO possessed poor HER activity but favorable NRR activity. CoO quantum dots (2–5 nm) supported on graphene exhibited a high NH3 yield of 21.5 μg h−1 mg−1 and a faradaic efficiency of 8.3% at −0.6 V vs. RHE under ambient conditions, superior to most of the reported NRR catalysts.

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