The photoluminescence behavior of CdS quantum dots in initial growth stage was studied in connection with an annealing process. Compared to the as-synthesized CdS quantum dots (quantum efficiency ≅ 1%), the heat-treated sample showed enhanced luminescence properties (quantum efficiency ≅ 29%) with a narrow band-edge emission. The simple annealing process diminished the accumulated defect states within the nanoparticles and thereby reduced the nonradiative recombination, which was confirmed by diffraction, absorption, and time-resolved photoluminescence. Consequently, the highly luminescent and defect-free nanoparticles were obtained by a facile and straightforward process.
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http://dx.doi.org/10.1186/1556-276X-7-482 | DOI Listing |
Heliyon
January 2025
Department of Chemistry, An-Najah National University, Nablus, Palestine.
While CuS/TiO₂ has been previously synthesized and employed in a limited number of photodegradation studies, the current study investigated its effectiveness for TC degradation under UV-visible light irradiation. CuS is known to be a nontoxic, environmentally friendly material; hence, it has great potential as an alternative to CdS and CdSe, which are used conventionally as sensitizers. In this work, the CuS/TiO₂ photocatalysts achieved a maximum 95 % removal of TC at an initial concentration of 20 ppm, confirming the good utilization of active sites.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
Using many-body perturbation theory, we study the optical properties of phenylthiolate-capped cadmium sulfide nanoparticles to understand the origin of the experimentally observed blue shift in those properties with decreasing particle size. We show that the absorption spectra predicted by many-body perturbation theory agree well with the experimentally measured spectra. The results of our calculations demonstrate that all low-energy excited states correspond to a mixture of two fundamental types of excitations: intraligand and ligand-to-metal charge-transfer excitations.
View Article and Find Full Text PDFMikrochim Acta
January 2025
School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, China.
A ratiometric fluorescent nanoprobe (CDs-Rho), synthesized through the simple covalent amide linkage between carbon dots (CDs) and pH-sensitive rhodamine dye (Rho), was designed for the precise sensing and imaging of extremely alkaline environments. The sensing mechanism involves the opposite pH-dependent fluorescence changes in CDs and Rho, respectively, coupled with pH-regulated FRET efficiency from CDs to Rho. The nanoprobe features a wide pH response window from pH 7.
View Article and Find Full Text PDFMolecules
January 2025
Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
The use of biomass feedstocks for producing high-value-added chemicals is gaining significant attention in the academic community. In this study, near-infrared carbon dots (NIR-CDs) with antimicrobial and bioimaging functions were prepared from branches and leaves using a novel green synthesis approach. The spectral properties of the synthesized NIR-CDs were characterized by ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry, Middle Tennessee State University, 440 Friendship Street, Murfreesboro, TN 37132, USA.
Elevated dopamine (DA) levels in urine denote neuroblastoma, a pediatric cancer. Saccharide-derived carbon dots (CDs) were applied to assay DA detection in simulated urine (SU) while delineating the effects of graphene defect density on electrocatalytic activity. CDs were hydrothermally synthesized to vary graphene defect densities using sucrose, raffinose, and palatinose, depositing them onto glassy carbon electrodes (GCEs).
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