Diffusion of Solvent-Separated Ion Pairs Controls Back Electron Transfer Rate in Graphene Quantum Dots

2018 ◽  
Vol 122 (28) ◽  
pp. 15819-15825 ◽  
Author(s):  
Ayan Bhattacharyya ◽  
Soumalya Mukherjee ◽  
Anju Chadha ◽  
Edamana Prasad
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Transfer Rate ◽  
Ion Pairs ◽  
Graphene Quantum Dots ◽  
Electron Transfer Rate ◽  
Back Electron Transfer

Photovoltaic performances of type-II dye-sensitized solar cells based on catechol dye sensitizers: retardation of back-electron transfer by PET (photo-induced electron transfer)

2017 ◽  
Vol 1 (11) ◽  
pp. 2243-2255 ◽  
Author(s):  
Yousuke Ooyama ◽  
Kosuke Yamaji ◽  
Joji Ohshita
Keyword(s):  
Electron Transfer ◽  
Solar Cells ◽  
Transfer Rate ◽  
Dye Sensitized Solar Cells ◽  
Type Ii ◽  
Electron Transfer Rate ◽  
Dye Sensitized ◽  
Back Electron Transfer ◽  
Photo Induced Electron Transfer ◽  
Sensitized Solar Cells

Catechol dyes (CAT-PET) possessing PET (photo-induced electron transfer) characteristics, which make it possible to retard the back-electron transfer rate, are an efficient dye sensitizer for type-II DSSCs.

Charge transfer modeling in monolayer circular graphene quantum dots–ZnO nanowires system for application in photovoltaic devices

2017 ◽  
Vol 31 (02) ◽  
pp. 1650253 ◽  
Author(s):  
Shahryar Tamandani ◽  
Ghafar Darvish
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Transfer Rate ◽  
Graphene Quantum Dots ◽  
Analytical Calculation ◽  
Zno Nanowires ◽  
Photovoltaic Devices ◽  
Electron Transfer Rate ◽  
Cdse Qds ◽  
Donor And Acceptor

We investigate electron transport between circular graphene quantum dots (CGQDs) and ZnO nanowires (ZnO NWs). This structure can be used as donor and acceptor in hybrid solar cells. We consider circular quantum dots (QDs) and use analytical calculation in order to estimate wavefunctions of GQD and ZnO NWs. After calculating the wavefunctions overlap, we use Marcus relation in order to calculate electron transfer rate. Also, we calculate this transfer rate for CdSe QDs–ZnO NWs system. Results from analytical calculation show that the transfer rate is limited to 10[Formula: see text] s[Formula: see text]. This result is in agreement with experimental results which are reported earlier. Such systems could be suitable for solar cells.

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Transfer Rate ◽  
Photocatalytic Performance ◽  
Light Exposure ◽  
Au Nanoparticle ◽  
Electron Transfer Rate ◽  
Au Nps ◽  
Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

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