We review here the background and the experiments that led to the concept of excitation energy transfer among photosystem (PS) II units. On the basis of a kinetic analysis of oxygen evolution and chlorophyll a fluorescence yield, the authors showed, in 1964, that the PS II photochemical reaction involved in the formation of oxygen is not a first-order process. We concluded that excitation energy localized in a 'photosynthetic unit' including a reduced primary acceptor is transferred with a high probability to neighboring PS II units. Here, the beginnings and the original data of this topic are presented.
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http://dx.doi.org/10.1023/A:1024908829819 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Department of Physics, Liaoning University, Shenyang 110036, Liaoning, China. Electronic address:
To investigate the influence of the position and quantity of thiophene or acetylene groups on the photoelectric properties of dye-sensitized solar cells (DSSCs), density functional theory (DFT) were employed to simulate five zinc porphyrin dye molecules (T-3, T-3-D, T-3-A, T-3-AD, and T-3-ace). The optimized geometry indicated that T-3-ace possessed superior planar properties, attributed to incorporating the acetylene groups, facilitating the charge transfer process. The lower lowest unoccupied molecular orbital (LUMO) energy levels of T-3-ace and T-3-D suggested that introducing thiophene or acetylene groups on the donor side enhanced the electron absorption capability of the dyes.
View Article and Find Full Text PDFWater Sci Technol
January 2025
China Construction Fifth Engineering Division Co., Ltd, Changsha, Hunan 410004, China.
Road runoff underwent treatment using a filter filled with sludge from drinking water treatment plants to assess its capacity for removing dissolved organic matter (DOM). This evaluation utilized resin fractionation, gel permeation chromatography, three-dimensional excitation-emission matrix fluorescence spectroscopy, and UV-Visible spectroscopy. The filter demonstrated enhanced efficiency in removing dissolved organic carbon, achieving removal rates between 70 and 80%.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India.
We report nonconjugated monocyclic dienes (nCMDs) as unique photoswitchable molecules that hold promise for harvesting substantial solar energy and storing it for extended durations. Herein, cyclohepta-1,4-diene and its N-heterocyclic analogue have been considered as prototypical models for investigating photoswitching behavior in nCMDs. Initially, the nonradiative deactivation pathway of nCMD from the low-lying excited state to the [2 + 2]-cycloadduct has been evaluated.
View Article and Find Full Text PDFFront Chem
January 2025
Nanophotonics Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli, India.
An interesting approach of including an upconverter in the MoS counter electrode can yield broadband light harvesting Pt-free DSSC assembly. Here different upconverter (UC) nanoparticles (Yb, Er incorporated NaYF, YF, CeO & YO) were synthesized and loaded in MoS thin film by hydrothermal method. The inclusion of UCs in MoS films exposed without any secondary formation of upconverters and the uniform deposition of the films are confirmed through XRD and FESEM analysis respectively.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Physics and Engineering, Albany State University, GA 31707. USA. Electronic address:
This work represents a comprehensive study of the ground vibrational state of C-13 substituted methanol using very high-resolution far-infrared (FIR) and infrared (IR) Synchrotron Radiation spectra recorded with a very high signal-to-noise (S/N) ratio in the entire region from 40to5000cm, at the Canadian Light sources. High resolution combined with a high S/N ratio allowed the recording to be done with an unprecedented resolution of about 0.0017cm.
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