Fluorescent organic dyes photobleach under intense light. Graphene has been shown to improve the photo-stability of organic dyes. In this paper, we investigated the Raman spectroscopy and photo-bleaching kinetics of dyes in the absence/presence of chemical vapor deposition (CVD)-grown graphene. We show that graphene enhances the Raman signal of a wide range of dyes. The photo-bleaching of the dyes was reduced when the dyes were in contact with graphene. In contrast, monolayer hexagonal boron nitride (h-BN) was much less effective in reducing the photo-bleaching rate of the dyes. We attribute the suppression of photo-bleaching to the energy or electron transfer from dye to graphene. The results highlight the potential of CVD graphene as a substrate for protecting and enhancing Raman response of organic dyes.
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http://dx.doi.org/10.3390/nano7100337 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Laboratory of Organic Chemistry, Tarsadia Institute of Chemical Science, Uka Tarsadia University, Maliba Campus, Gopal Vidyanagar, Bardoli-Mahuva Road, Tarsadi 394650 Surat Gujarat India. Electronic address:
A single molecule sensor for several analytes is indeed desired by the scientists around the world due to obvious advantages. In this report we present a new class of Lophine incorporated azo dyes that has capacity of differential colorimetric detection of several metal ions. Interestingly the sensor was found to have pH dependent selective response towards several metals.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
In this study, copper nanoparticles with an average particle size of 2-4 nm were synthesized using the green extract of Thunb. The catalytic activity and dye degradation efficiency of Cu NPs were evaluated using ultraviolet spectroscopy. To confirm that Cu NPs can continuously remove organic dyes, this study used Cu/Lj-C composite material adsorbed on cotton balls as a simulated bed to study the cyclic catalytic activity of Cu NPs for the reduction of methylene blue by sodium borohydride (NaBH).
View Article and Find Full Text PDFGels
January 2025
National Institute for Lasers, Plasma and Radiation Physics, 077125 Măgurele, Romania.
Stimulus-responsive hydrogels have emerged as versatile materials for environmental and wastewater treatment applications due to their ability to adapt to changing environmental conditions. This review highlights recent advances in the design, synthesis, and functionalization of such hydrogels, focusing on their environmental applications. Various synthesis techniques, including radical polymerization, grafting, and copolymerization, enable the development of hydrogels with tailored properties such as enhanced adsorption capacity, selectivity, and reusability.
View Article and Find Full Text PDFNanoscale
January 2025
Dept. of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
Identifying facile strategies for hierarchically structuring crystalline porous materials is critical for realizing diffusion length scales suitable for broad applications. Here, we elucidate synthesis-structure-function relations governing how room temperature catalytic conditions can be exploited to tune covalent organic framework (COF) growth and thereby access unique hierarchical morphologies without the need to introduce secondary templates or structure directing molecules. Specifically, we demonstrate how scandium triflate, an efficient catalyst involved in the synthesis of imine-based COFs, can be exploited as an effective growth modifier capable of selectively titrating terminal amines on 2D COF layers to facilitate anisotropic crystal growth.
View Article and Find Full Text PDFChemistry
January 2025
Justus-Liebig Universität, Institut für Organische Chemie, Heinrich-Buff-Ring 17, 35392, Giessen, GERMANY.
Aryl diazenes, particularly azobenzenes (AB), represent a versatile class of compounds with significant historical and practical relevance, ranging from dyes to molecular machines, solar thermal and electrochemical storage. Their oxygen-substituted counterparts, azoxybenzenes (AOB), share structural similarities but have been less explored, especially in energy storage applications. This study investigates the redox properties of AOB, comparing them to AB, and evaluates their potential as redox-active materials for energy storage systems.
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