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Yang X, Wang T, Li Y, Hu Y, Wang Y, Xie W. Long-lived carriers-promoted photocatalytic deuteration of halides with D 2O as the deuterium source over Cu doped quantum dots. J Colloid Interface Sci 2024; 678:191-199. [PMID: 39293363 DOI: 10.1016/j.jcis.2024.09.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 09/01/2024] [Accepted: 09/04/2024] [Indexed: 09/20/2024]
Abstract
Deuterium labeling is a highly valuable yet challenging subject of research in various scientific fields. Conventional deuteration methods often involve harsh reaction conditions and suffer from limited reactivity and selectivity. Herein, we report a visible light-driven C-X (X = halogen) to C-D (D = deuterium) exchange strategy over copper-doped cadmium sulfide quantum dots (Cu-CdS QDs) under mild conditions, eliminating the need for noble metal catalysts and expensive deuterium sources. The conversion of aryl halides into deuterated products using Cu-CdS QDs reaches up to 99%, which is four times higher than that achieved using pristine CdS QDs. The substantial enhancement in the photocatalytic activity of the QDs can be primarily attributed to the generation of long-lived charge carriers (approximately 6 μs) induced by Cu doping. Mechanistic studies reveal that the Cu dopants considerably retard the recombination of photoinduced carriers by creating intermediate energy levels that serve as hole trapping centers in CdS QDs, thereby improving the electron utilization efficiency in energetically demanding photoreduction reactions. Additionally, the introduction of Cu increases the energy offset between the conduction band of CdS QDs and molecular acceptors, facilitating the electron transfer process. Upon visible light irradiation, a series of aryl halides can be efficiently converted into the desired deuterated compounds using D2O as the deuterium source. This work demonstrates that regulating charge carrier dynamics in ultrasmall QD-based photocatalysts is a promising strategy for promoting organic transformations.
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Affiliation(s)
- Xian Yang
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Teng Wang
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yonglong Li
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yanfang Hu
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Ying Wang
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Wei Xie
- State Key Laboratory of Advanced Chemical Power Sources, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin Key Lab of Biosensing & Molecular Recognition, Haihe Laboratory of Sustainable Chemical Transformations, Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin 300071, China.
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Steenbock T, Dittmann T, Kumar S, Bester G. Ligand-Induced Symmetry Breaking as the Origin of Multiexponential Photoluminescence Decay in CdSe Quantum Dots. J Phys Chem Lett 2023; 14:8859-8866. [PMID: 37756012 DOI: 10.1021/acs.jpclett.3c02056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
The bright photoluminescence (PL) of colloidal CdSe quantum dots (QDs) makes them interesting for optical applications. For most of them, well-defined PL properties, dominated by a single excitonic state, are required. However, in many PL experiments with QD ensembles, multiexponential decay was observed. On the basis of spin-orbit density functional theory and screened configuration interaction calculations, we show that highly symmetric and defect-free CdSe QDs with diameters of 1.7 and 2.0 nm possess a multiexponential low-temperature PL at the single-dot level. This is a consequence of ligand-induced symmetry breaking with a subsequent rearrangement of the lowest eight excitonic states in two sets of four singly degenerate excitonic states. For each set, the lowest state is dark and the other three are bright. We find that the splitting between the sets can be modified by the coverage and choice of the ligand, which facilitates the engineering of the PL properties of CdSe QDs.
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Affiliation(s)
- Torben Steenbock
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Tobias Dittmann
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Surender Kumar
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Gabriel Bester
- Department of Chemistry and Physics, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, Hamburg 22761, Germany
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Qi MY, Tang ZR, Xu YJ. Near Field Scattering Optical Model-Based Catalyst Design for Artificial Photoredox Transformation. ACS Catal 2023. [DOI: 10.1021/acscatal.2c06397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Affiliation(s)
- Ming-Yu Qi
- College of Chemistry, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China
| | - Zi-Rong Tang
- College of Chemistry, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China
| | - Yi-Jun Xu
- College of Chemistry, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China
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Wamsley M, Wathudura P, Hu J, Zhang D. Integrating-Sphere-Assisted Resonance Synchronous Spectroscopy for the Quantification of Material Double-Beam UV-Vis Absorption and Scattering Extinction. Anal Chem 2022; 94:11610-11618. [PMID: 35960824 DOI: 10.1021/acs.analchem.2c02037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Integrating spheres (IS) have been used extensively for the characterization of light absorption in turbid samples. However, converting the IS-based sample absorption coefficient to the UV-vis absorbance quantified with a double-beam UV-vis spectrophotometer is challenging. Herein, we report an integrating-sphere-assisted resonance synchronous (ISARS) spectroscopy method performed with conventional spectrofluorometers equipped with an integrating-sphere accessory. Mathematical models and experimental procedures for quantifying the sample, solvent, and instrument-baseline ISARS intensity spectra were provided. A three-parameter analytical model has been developed for correlating the ISARS-based UV-vis absorbance and the absorbance measured with double-beam instruments. This ISARS method enables the quantitative separation of light absorption and scattering contribution to the sample UV-vis extinction spectrum measured with double-beam UV-vis spectrophotometers. Example applications of this ISARS technique are demonstrated with a series of representative samples differing significantly in their optical complexities, from approximately pure absorbers, pure scatterers, to simultaneous light absorbers, scatterers, and emitters under resonance excitation and detection conditions.
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Affiliation(s)
- Max Wamsley
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Pathum Wathudura
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Juan Hu
- Department of Mathematical Sciences, DePaul University, Chicago, Illinois 60604, United States
| | - Dongmao Zhang
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
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