The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)...The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)degradation.The electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of CDs.Finally,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry technique.This research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.展开更多
SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish ...SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.展开更多
The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals...The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals and accelerate the aging of human cells,causing a series of diseases.Hence,the cost-effective and rapid detection of mercury and H_(2)O_(2)is of urgent requirement and significance.Here,we synthesized emerging graphitic carbon nitride quantum dots(g-CNQDs)with high fluorescence quantum yield(FLQY)of 42.69%via a bottom-up strategy by a facile one-step hydrothermal method.The g-CNQDs can detect the H_(2)O_(2)and Hg^(2+)through the fluorescence quenching effect between g-CNQDs and detected substances.With the presence of KI,g-CNQDs show concentration-dependent fluorescence toward H_(2)O_(2),with a wide detection range of 1–1000μmolL^(-1)and a low detection limit of 0.23μmolL^(-1).The g-CNQDs also show sensitivity toward Hg^(2+)with a detection range of 0–0.1μmolL^(-1)and a detection limit of 0.038μmolL^(-1).This dual-function detection of g-CNQDs has better practical application capability compared to other quantum dot detection.This study may provide a new strategy for g-CNQDs preparation and construct a fluorescence probe that can be used in various systems involving H_(2)O_(2)and Hg^(2+),providing better support for future bifunctional or multifunction studies.展开更多
2D MXene(Ti_(3)CNT_(x))has been considered as the most promising electrode material for flexible supercapacitors owing to its metallic conductivity,ultra-high capacitance,and excellent flexibility.However,it suffers f...2D MXene(Ti_(3)CNT_(x))has been considered as the most promising electrode material for flexible supercapacitors owing to its metallic conductivity,ultra-high capacitance,and excellent flexibility.However,it suffers from a severe restacking problem during the electrode fabrication process,limiting the ion transport kinetics and the accessibility of ions in the electrodes,especially in the direction normal to the electrode surface.Herein,we report a NH_(3)-induced in situ etching strategy to fabricate 3D-interconnected porous MXene/carbon dots(p-MC)films for high-performance flexible supercapacitor.The pre-intercalated carbon dots(CDs)first prevent the restacking of MXene to expose more inner electrochemical active sites.The partially decomposed CDs generate NH_(3)for in situ etching of MXene nanosheets toward 3D-interconnected p-MC films.Benefiting from the structural merits and the 3D-interconnected ionic transmission channels,p-MC film electrodes achieve excellent gravimetric capacitance(688.9 F g^(-1)at 2 A g^(-1))and superior rate capability.Moreover,the optimized p-MC electrode is assembled into an asymmetric solid-state flexible supercapacitor with high energy density and superior cycling stability,demonstrating the great promise of p-MC electrode for practical applications.展开更多
Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterial...Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterials,which have been considered for corrosion protection applications in recent years due to their corrosion inhibition effect,fluorescence,low toxicity,facile chemical modification,and cost-effectiveness.This study provides a comprehensive overview of the synthesis,physical and chemical properties,and anticorrosion mechanisms of functionalized CDs.First,the corrosion inhibition performance of different types of CDs is introduced,followed by discussion on their application in the development of smart protective coatings with self-healing and/or self-reporting properties.The effective barrier formed by CDs in the coatings can inhibit the spread of local damage and achieve self-healing behavior.In addition,diverse functional groups on CDs can interact with Fe^(3+)and H^(+)ions generated during the corrosion process;this interaction changes their fluorescence,thereby demonstrating self-reporting behavior.Moreover,challenges and prospects for the development of CD-based corrosion protection systems are also presented.展开更多
Interfacial imperfections between the perovskite layer and the electron transport layer(ETL)in perovskite solar cells(PSCs)can lead to performance loss and negatively influence long-term operational stability.Here,we ...Interfacial imperfections between the perovskite layer and the electron transport layer(ETL)in perovskite solar cells(PSCs)can lead to performance loss and negatively influence long-term operational stability.Here,we introduce an interface engineering method to modify the interface between perovskite and ETL by using multifunctional carbon dots(CDs).C=O in the CDs can chelate with the uncoordinated Pb2+in the perovskite material,inhibit interfacial recombination,and enhance the performance and stability of device.In addition,–OH in CDs forms hydrogen bonds with I-and organic cation in perovskite,inhibiting light-induced I2release and organic cation volatilization,causing irreversible degradation of perovskite films,thereby enhancing the long-term operational stability of PSCs.Consequently,we achieve the champion inverted device with an efficiency of 24.02%.The CDs-treated PSCs exhibit high operational stability,and the maximum power point tracking only attenuates by 12.5%after 1000 h.Interfacial modification engineering supported by multifunctional quantum dots can accelerate the road to stable PSCs.展开更多
Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-ti...Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-tion spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide(MoS_(2)).Transient absorption plots showed photoinduced absorption and stimulated emission features,which involved the intrinsic and defect states of CQDs.Adding MoS_(2)to CQDs solution,the lowest unoccupied molecular orbital of CQDs transferred energy to MoS_(2),which quenched the intrinsic emission at 390 nm.With addition of MoS_(2),CQD-MoS_(2)composites quenched defect emission at 490 nm and upward absorption,which originated from another energy transfer from the defect state.Two energy transfer paths between CQDs and MoS_(2)were efficiently manipulated by changing the concentration of MoS_(2),which laid a foundation for improving device performance.展开更多
Highly conjugated multiwalled carbon nanotube-quantum dot heterojunctions were synthesized by ethylene carbodiimide coupling procedure. The functional multiwalled carbon nanotube with carboxylic groups on sidewall cou...Highly conjugated multiwalled carbon nanotube-quantum dot heterojunctions were synthesized by ethylene carbodiimide coupling procedure. The functional multiwalled carbon nanotube with carboxylic groups on sidewall could react with the amino group of L-cysteine capped CdSe quantum dots and then resulted in nanotube-quantum dot heterojunctions. Scanning electron microscopy was used to characterize the heterojunctions.展开更多
Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target ana...Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions,organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal,solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.展开更多
Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and su...Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and sulfur(S)-doped CDs was developed via a hydrothermal method using methionine and citric acid as raw materials. The as-prepared CDs exhibit excellent optical properties and good biocompatibility. The spherical N,S-doped CDs have an average diameter of 5 nm. They consist of C, O, N and S, and take on excellent water solubility due to the hydroxyl and carboxyl, amino groups on the surface.The CDs have a photoluminescence quantum yield of 13.8% using quinine sulfate as a reference; the average fluorescence lifetime of the CDs was 3.67 ns. The CDs solution present good photoluminescence properties, and the maximum excitation wavelength and emission wavelength locate at 330 nm and405 nm, respectively. In addition, their fluorescence intensity almost does not change under the conditions of acid, alkali, and high salt, which indicated their anti-photobleaching property and good light stability. Based on the good biocompatibility and strong fluorescence emission of the CDs, they can be used as fluorescent imaging reagents.展开更多
Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent pho...Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.展开更多
In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluo...In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.展开更多
Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield w...Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield with more than 50%.The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials,manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity.Moreover,the nitrogen-doped reduced graphene oxide(N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO.A novel alkaline aqueous battery assembled by these materials displays a specific energy(50.2 Wh kg^−1),ultrahigh specific power(9.7 kW kg^−1)and excellent cycling performance with 91.5%of capacity retention at 3 A g^−1 for 5000 cycles.The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.展开更多
As the abundant biopolymer, cellulose can be used as a feedstock for chemicals and materials. Effective conversion of cellulose by simple processes is a key point. Degradation of cellulose in its homogeneous solution ...As the abundant biopolymer, cellulose can be used as a feedstock for chemicals and materials. Effective conversion of cellulose by simple processes is a key point. Degradation of cellulose in its homogeneous solution is attractive for the molecular chains are free and spread. Here,microcrystalline cellulose was first dissolved in aqueous solution of Na OH and urea, and then hydrothermal reaction was carried out at various temperature and time. Fluorescence carbon dots(CDs) were generated accompanied with six organic acids: oxalic acid, formic acid, malonic acid, lactic acid, acetic acid, and fumaric acid. The yields of all organic acids and CDs, and the fluorescence quantum yield(QY) of CDs were studied at different reaction conditions. It was found that the maximum yield of organic acids and CDs are 80.1% and 6.03%, respectively, and the highest QY of the CDs is 10.9%. Fluorescence studies reveal that the as-prepared CDs has efficient selectivity and sensitivity toward iron ions in acidic condition, indicating it is a potential fluorescent sensor to the detection of Fe3+. Importantly, it provides a panorama to summary the degradation routes of cellulose in its homogeneous aqueous solution with both organic molecules and CDs as products.展开更多
β-lactam antibiotics in aquatic environment have severely damaged ecological stability and caused a series of environmental pollution problems to be solved urgently.Herein,a novel composite photocatalyst prepared by ...β-lactam antibiotics in aquatic environment have severely damaged ecological stability and caused a series of environmental pollution problems to be solved urgently.Herein,a novel composite photocatalyst prepared by loading carbon dots(CDs)onto rod-like CoFe_(2)O_(4)(CFO),which can effectively degrade amoxicillin(AMX)by photocata lytic/peroxy mono sulfate(PMS)activation under visible light irradiation.The degradation results exhibits that the optimal degradation efficiency with 97.5%within 80 min is achievd by the CDs-CFO-5 composite.Such enhanced activity is ascribed to the introduction of CDs that effectively improves the separation efficiency of photogenerated electron pairs and creates new active sites as electron bridges that improve the photocata lytic performance.More importantly,a strong synergistic between CDs and photo-induced electrons generated from CFO can further activiate PMS to provide more SO4-·and·OH radicals for boosting the degradation ability towards AMX.The present study aims to elucidate positive role of CDs in photocata lytic/peroxy monosulfate activation during the degradation reaction.展开更多
As a new member of carbon material family, carbon quantum dots (CQDs) have attracted tremendous attentions for their potentials in the heterogeneous photocatalysis applications. Due to the unique microstructure and op...As a new member of carbon material family, carbon quantum dots (CQDs) have attracted tremendous attentions for their potentials in the heterogeneous photocatalysis applications. Due to the unique microstructure and optical properties, the roles of CQDs played in the CQDs-based photocatalytic systems have been found to be diverse with the continuous researches in this regard. Herein, we provide a concise minireview to elaborate the multifarious roles of CQDs in photocatalysis, including photoelectron mediator and acceptor, photosensitizer, photocatalyst, reducing agent for metal salt, enhancing adsorption capacity and spectral converter. In addition, the perspectives on future research trends and challenges are proposed, which are anticipated to stimulate further research into this promising field on designing a variety of efficient CQDs-based photocatalysts for solar energy conversion. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.展开更多
Zero-dimensional(0D)carbon quantum dots(CQDs),as a nanocarbon material in the carbon family,have garnered increasing attention in recent years due to their outstanding features of low cost,nontoxicity,large surface ar...Zero-dimensional(0D)carbon quantum dots(CQDs),as a nanocarbon material in the carbon family,have garnered increasing attention in recent years due to their outstanding features of low cost,nontoxicity,large surface area,high electrical conductivity,and rich surface functional groups.By virtue of their rapid electron transfer and large surface area,CQDs also emerge as promising functional materials for the applications in energy-conversion sectors through electrocatalysis.Besides,the rich functional groups on the surface of CQDs offer abundant anchoring sites and active sites for the engineering of multicomponent and high-performance composite materials.More importantly,the heteroatom in the CQDs could effectively tailor the charge distribution to promote the electron transfer via internal interactions,which is crucial to the enhancement of electrocatalytic performance.Herein,an overview about recent progress in preparing CQDs-based composites and employing them as promising electrode materials to promote the catalytic activity and stability for electrocatalysis is provided.The introduced CQDs could enhance the conductivity,modify the morphology and crystal phase,optimize the electronic structure,and provide more active centers and defect sites of composites.After establishing a deep understanding of the relationship between CQDs and electrocatalytic performances,the issues and challenges for the development of CQDs-based composites are discussed.展开更多
Water-soluble CdS quantum dots(CdS-QDs) capped with thioglycohc acid were easily prepared, and a detection method of adriamycin was presented based on the fluorescence quenching of CdS-QDs. It was found that a compl...Water-soluble CdS quantum dots(CdS-QDs) capped with thioglycohc acid were easily prepared, and a detection method of adriamycin was presented based on the fluorescence quenching of CdS-QDs. It was found that a complex could be formed between cetyhrimethyl ammonium bromide(CTAB) and CdS-QDs by using electrostatic interaction in Britton-Robinson(BR) buffer at pH = 7.00, and the strong fluorescence emission of the complex was observed at 500 nm when the complex was excited at 378 run. The presence of adriamycin, however, could strongly quench the fluorescence through hydrophobic interaction. The overall quenching percentage as a function of adriamycin concentration matches the Stern-Volmer equation very well. These properties make CdS-QDs a potential fluorescence probe for the detection of adriamycin. The detection hmit(3σ) of adriamycin is approximately 10^-9 mol/L.展开更多
Safe, sustainable, and green production of hydro gen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the developm...Safe, sustainable, and green production of hydro gen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV,which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium.The overall process was performed in accordance with the principles of green chemistry using bio-based precursorsand aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.展开更多
基金the funding support from the National Natural Science Foundation of China(21906072,22006057)the Natural Science Foundation of Jiangsu Province(BK20190982)“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu Province。
文摘The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)degradation.The electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of CDs.Finally,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry technique.This research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.
基金National Natural Science Foundation of China,Grant/Award Number:51971065Innovation Program of Shanghai Municipal Education Commission,Grant/Award Number:2019-01-07-00-07-E00028。
文摘SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.
基金support from the Natural Science Foundation of Shandong Province(No.ZR2021 MB075)National Natural Science Foundation of China(No.51602297)the Opening Fund of State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering(No.2021-K53).
文摘The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals and accelerate the aging of human cells,causing a series of diseases.Hence,the cost-effective and rapid detection of mercury and H_(2)O_(2)is of urgent requirement and significance.Here,we synthesized emerging graphitic carbon nitride quantum dots(g-CNQDs)with high fluorescence quantum yield(FLQY)of 42.69%via a bottom-up strategy by a facile one-step hydrothermal method.The g-CNQDs can detect the H_(2)O_(2)and Hg^(2+)through the fluorescence quenching effect between g-CNQDs and detected substances.With the presence of KI,g-CNQDs show concentration-dependent fluorescence toward H_(2)O_(2),with a wide detection range of 1–1000μmolL^(-1)and a low detection limit of 0.23μmolL^(-1).The g-CNQDs also show sensitivity toward Hg^(2+)with a detection range of 0–0.1μmolL^(-1)and a detection limit of 0.038μmolL^(-1).This dual-function detection of g-CNQDs has better practical application capability compared to other quantum dot detection.This study may provide a new strategy for g-CNQDs preparation and construct a fluorescence probe that can be used in various systems involving H_(2)O_(2)and Hg^(2+),providing better support for future bifunctional or multifunction studies.
基金The authors gratefully acknowledge financial support from the National Natural Science Foundation of China(Grant Nos.21805261 and 51972277)Sichuan Science and Technology Program(Grant Nos.2021YFG0251 and 2022YFG0293)Fundamental Research Funds for the Central Universities(Grant No.2682021CX105)。
文摘2D MXene(Ti_(3)CNT_(x))has been considered as the most promising electrode material for flexible supercapacitors owing to its metallic conductivity,ultra-high capacitance,and excellent flexibility.However,it suffers from a severe restacking problem during the electrode fabrication process,limiting the ion transport kinetics and the accessibility of ions in the electrodes,especially in the direction normal to the electrode surface.Herein,we report a NH_(3)-induced in situ etching strategy to fabricate 3D-interconnected porous MXene/carbon dots(p-MC)films for high-performance flexible supercapacitor.The pre-intercalated carbon dots(CDs)first prevent the restacking of MXene to expose more inner electrochemical active sites.The partially decomposed CDs generate NH_(3)for in situ etching of MXene nanosheets toward 3D-interconnected p-MC films.Benefiting from the structural merits and the 3D-interconnected ionic transmission channels,p-MC film electrodes achieve excellent gravimetric capacitance(688.9 F g^(-1)at 2 A g^(-1))and superior rate capability.Moreover,the optimized p-MC electrode is assembled into an asymmetric solid-state flexible supercapacitor with high energy density and superior cycling stability,demonstrating the great promise of p-MC electrode for practical applications.
基金financially supported by the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(YESS,No.2020QNRC001)the National Science and Technology Resources Investigation Program of China(No.2021FY100603)the Fundamental Research Funds for the Central Universities(No.FRF-BD-20-28A2)。
文摘Metal corrosion causes significant economic losses,safety issues,and environmental pollution.Hence,its prevention is of immense research interest.Carbon dots(CDs)are a new class of zero-dimensional carbon nanomaterials,which have been considered for corrosion protection applications in recent years due to their corrosion inhibition effect,fluorescence,low toxicity,facile chemical modification,and cost-effectiveness.This study provides a comprehensive overview of the synthesis,physical and chemical properties,and anticorrosion mechanisms of functionalized CDs.First,the corrosion inhibition performance of different types of CDs is introduced,followed by discussion on their application in the development of smart protective coatings with self-healing and/or self-reporting properties.The effective barrier formed by CDs in the coatings can inhibit the spread of local damage and achieve self-healing behavior.In addition,diverse functional groups on CDs can interact with Fe^(3+)and H^(+)ions generated during the corrosion process;this interaction changes their fluorescence,thereby demonstrating self-reporting behavior.Moreover,challenges and prospects for the development of CD-based corrosion protection systems are also presented.
基金supported by the National Natural Science Foundation of China(52172237,22261142666)the Shaanxi International Cooperation Project(2020KWZ-018)+3 种基金the Shaanxi Science Fund for Distinguished Young Scholars(2022JC-21)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(2021-QZ-02)the Fundamental Research Funds for the Central Universities(D5000220033)the Hong Kong Scholars Program(XJ2022025)。
文摘Interfacial imperfections between the perovskite layer and the electron transport layer(ETL)in perovskite solar cells(PSCs)can lead to performance loss and negatively influence long-term operational stability.Here,we introduce an interface engineering method to modify the interface between perovskite and ETL by using multifunctional carbon dots(CDs).C=O in the CDs can chelate with the uncoordinated Pb2+in the perovskite material,inhibit interfacial recombination,and enhance the performance and stability of device.In addition,–OH in CDs forms hydrogen bonds with I-and organic cation in perovskite,inhibiting light-induced I2release and organic cation volatilization,causing irreversible degradation of perovskite films,thereby enhancing the long-term operational stability of PSCs.Consequently,we achieve the champion inverted device with an efficiency of 24.02%.The CDs-treated PSCs exhibit high operational stability,and the maximum power point tracking only attenuates by 12.5%after 1000 h.Interfacial modification engineering supported by multifunctional quantum dots can accelerate the road to stable PSCs.
基金supported by the National Natural Science Foundation of China(No.61805134 and No.11974229)Applied Basic Research Program in Shanxi Province,China(No.201801D221016 and No.202103021223254)+2 种基金Scientific and Technological Innovation Pro-grams of Higher Education Institutions in Shanxi(No.2020L0235 and No.2021L257)Linfen Key Re-search and Development Program(No.2028)Graduate Innovation Project in Shanxi Province(No.2022Y498).
文摘Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic devices.We combined steady-state and transient absorp-tion spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide(MoS_(2)).Transient absorption plots showed photoinduced absorption and stimulated emission features,which involved the intrinsic and defect states of CQDs.Adding MoS_(2)to CQDs solution,the lowest unoccupied molecular orbital of CQDs transferred energy to MoS_(2),which quenched the intrinsic emission at 390 nm.With addition of MoS_(2),CQD-MoS_(2)composites quenched defect emission at 490 nm and upward absorption,which originated from another energy transfer from the defect state.Two energy transfer paths between CQDs and MoS_(2)were efficiently manipulated by changing the concentration of MoS_(2),which laid a foundation for improving device performance.
基金supported by the National Natural Science Foundation of China(No.20705016)State Key Laboratory of Electroanalytical Chemistry(No.2008009)China Postdoctoral Science Foundation(No.20080431213).
文摘Highly conjugated multiwalled carbon nanotube-quantum dot heterojunctions were synthesized by ethylene carbodiimide coupling procedure. The functional multiwalled carbon nanotube with carboxylic groups on sidewall could react with the amino group of L-cysteine capped CdSe quantum dots and then resulted in nanotube-quantum dot heterojunctions. Scanning electron microscopy was used to characterize the heterojunctions.
基金supported by the National HighTech R&D Program of China (863 program, 2011AA050504)National Natural Science Foundation of China (21171117 and 61376003)+4 种基金Program for New Century Excellent Talents in University (NCET-12-0356)Shanghai Natural Science Foundation (13ZR1456600)Shanghai Science and Technology Grant (12JC1405700)Shanghai Pujiang Program (11PJD011)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and Medical-Engineering Crossover Fund (YG2012MS40 and YG2012MS32) of Shanghai Jiao Tong University
文摘Carbon dots(CDs), as a new member of carbon nanomaterial family, have aroused great interest since their discovery in 2004. Because of their outstanding water solubility, high sensitivity and selectivity to target analytes, low toxicity, favorable biocompatibility, and excellent photostability, researchers from diverse disciplines have come together to further develop the fundamental properties of CDs. Many methods for the production of CDs have been reported, therein, hydrothermal and solvothermal technology needs simple equipments, and microwave synthesis needs less reaction time, hence these methods become current common synthesis methods, in which many precursors have been applied to produce CDs. Due to their excellent fluorescence, CDs have made impressive strides in sensitivity and selectivity to a diverse array of salt ions,organic/biological molecules and target gases. The development of CDs as nanoprobes is still in its infancy, but continued progress may lead to their integration into environmental and biological applications. Hydrothermal,solvothermal, and microwave synthesis of fluorescent carbon dots and their detection applications as nanoprobes in salt ions, organic/biological molecules, and target gases will be reviewed.
基金financially supported by the National Natural Science Foundation of China (NSFC, No. 21535006 and No. 21705132)the Fundamental Research Funds for the Central Universities (XDJK2017C065)
文摘Heteroatom-doped carbon dots(CDs) have attracted extensive interest because of their improved electronic and fluorescence properties with heteroatom doping. In this study, a new synthetic method for nitrogen(N) and sulfur(S)-doped CDs was developed via a hydrothermal method using methionine and citric acid as raw materials. The as-prepared CDs exhibit excellent optical properties and good biocompatibility. The spherical N,S-doped CDs have an average diameter of 5 nm. They consist of C, O, N and S, and take on excellent water solubility due to the hydroxyl and carboxyl, amino groups on the surface.The CDs have a photoluminescence quantum yield of 13.8% using quinine sulfate as a reference; the average fluorescence lifetime of the CDs was 3.67 ns. The CDs solution present good photoluminescence properties, and the maximum excitation wavelength and emission wavelength locate at 330 nm and405 nm, respectively. In addition, their fluorescence intensity almost does not change under the conditions of acid, alkali, and high salt, which indicated their anti-photobleaching property and good light stability. Based on the good biocompatibility and strong fluorescence emission of the CDs, they can be used as fluorescent imaging reagents.
基金supported by NTUA*STAR Silicon Technologies Centre of Excellence under the program Grant (No.11235100003)Grants Tier 2 MOE2017-T2-2-002 (No.M402110000) from Ministry of Educationthe NRF-ANR Joint Call 2017 Research Grant (No. M419640000) from the National Research Foundation,Singapore
文摘Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.
文摘In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.
基金financially supported by National Natural Science Foundation of China(21601057)Hunan Provincial Natural Science Foundation of China(2018JJ3116)Excellent Youth Fund of Hunan Provincial Education Department(18B298)
文摘Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield with more than 50%.The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials,manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity.Moreover,the nitrogen-doped reduced graphene oxide(N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO.A novel alkaline aqueous battery assembled by these materials displays a specific energy(50.2 Wh kg^−1),ultrahigh specific power(9.7 kW kg^−1)and excellent cycling performance with 91.5%of capacity retention at 3 A g^−1 for 5000 cycles.The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.
基金supported by the National Natural Science Foundation of China (No. 51373162 and 51673180)
文摘As the abundant biopolymer, cellulose can be used as a feedstock for chemicals and materials. Effective conversion of cellulose by simple processes is a key point. Degradation of cellulose in its homogeneous solution is attractive for the molecular chains are free and spread. Here,microcrystalline cellulose was first dissolved in aqueous solution of Na OH and urea, and then hydrothermal reaction was carried out at various temperature and time. Fluorescence carbon dots(CDs) were generated accompanied with six organic acids: oxalic acid, formic acid, malonic acid, lactic acid, acetic acid, and fumaric acid. The yields of all organic acids and CDs, and the fluorescence quantum yield(QY) of CDs were studied at different reaction conditions. It was found that the maximum yield of organic acids and CDs are 80.1% and 6.03%, respectively, and the highest QY of the CDs is 10.9%. Fluorescence studies reveal that the as-prepared CDs has efficient selectivity and sensitivity toward iron ions in acidic condition, indicating it is a potential fluorescent sensor to the detection of Fe3+. Importantly, it provides a panorama to summary the degradation routes of cellulose in its homogeneous aqueous solution with both organic molecules and CDs as products.
基金founding support from the National Natural Science Foundation of China(Nos.21906072,22006057 and 31971616)the Natural Science Foundation of Jiangsu Province(BK20190982)+4 种基金“Doctor of Mass Entrepreneurship and Innovation”Project in Jiangsu Province,Henan Postdoctoral Foundation(202003013)Doctoral Scientific Research Foundation of Jiangsu University of Science and Technology(China)(1062931806 and 1142931803)the Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20200039KJ)the Science and Technology Research Project of Jilin City(20190104120,201830811)the Project of Jilin Provincial Science and Technology Development Plan(20190201277JC,20200301046RQ,YDZJ202101ZYTS070)。
文摘β-lactam antibiotics in aquatic environment have severely damaged ecological stability and caused a series of environmental pollution problems to be solved urgently.Herein,a novel composite photocatalyst prepared by loading carbon dots(CDs)onto rod-like CoFe_(2)O_(4)(CFO),which can effectively degrade amoxicillin(AMX)by photocata lytic/peroxy mono sulfate(PMS)activation under visible light irradiation.The degradation results exhibits that the optimal degradation efficiency with 97.5%within 80 min is achievd by the CDs-CFO-5 composite.Such enhanced activity is ascribed to the introduction of CDs that effectively improves the separation efficiency of photogenerated electron pairs and creates new active sites as electron bridges that improve the photocata lytic performance.More importantly,a strong synergistic between CDs and photo-induced electrons generated from CFO can further activiate PMS to provide more SO4-·and·OH radicals for boosting the degradation ability towards AMX.The present study aims to elucidate positive role of CDs in photocata lytic/peroxy monosulfate activation during the degradation reaction.
基金financial support from the key project of the National Natural Science Foundation of China (U1463204)the project of National Natural Science Foundation of China (NSFC) (20903023,21173045)+4 种基金the Award Program for Minjiang Scholar Professorshipthe Natural Science Foundation (NSF) of Fujian Province for Distinguished Young Investigator Grant (2012J06003)the Independent Research Project of State Key Laboratory of Photocatalysis on Energy and Environment (No.2014A05)the 1st Program of Fujian Province for Top Creative Young Talentsthe Program for Returned High-Level Overseas Chinese Scholars of Fujian Province
文摘As a new member of carbon material family, carbon quantum dots (CQDs) have attracted tremendous attentions for their potentials in the heterogeneous photocatalysis applications. Due to the unique microstructure and optical properties, the roles of CQDs played in the CQDs-based photocatalytic systems have been found to be diverse with the continuous researches in this regard. Herein, we provide a concise minireview to elaborate the multifarious roles of CQDs in photocatalysis, including photoelectron mediator and acceptor, photosensitizer, photocatalyst, reducing agent for metal salt, enhancing adsorption capacity and spectral converter. In addition, the perspectives on future research trends and challenges are proposed, which are anticipated to stimulate further research into this promising field on designing a variety of efficient CQDs-based photocatalysts for solar energy conversion. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.
基金supported by The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJB150019)Youth Science and Technology Talents Enrollment Project of the Jiangsu Association of Science and Technology。
文摘Zero-dimensional(0D)carbon quantum dots(CQDs),as a nanocarbon material in the carbon family,have garnered increasing attention in recent years due to their outstanding features of low cost,nontoxicity,large surface area,high electrical conductivity,and rich surface functional groups.By virtue of their rapid electron transfer and large surface area,CQDs also emerge as promising functional materials for the applications in energy-conversion sectors through electrocatalysis.Besides,the rich functional groups on the surface of CQDs offer abundant anchoring sites and active sites for the engineering of multicomponent and high-performance composite materials.More importantly,the heteroatom in the CQDs could effectively tailor the charge distribution to promote the electron transfer via internal interactions,which is crucial to the enhancement of electrocatalytic performance.Herein,an overview about recent progress in preparing CQDs-based composites and employing them as promising electrode materials to promote the catalytic activity and stability for electrocatalysis is provided.The introduced CQDs could enhance the conductivity,modify the morphology and crystal phase,optimize the electronic structure,and provide more active centers and defect sites of composites.After establishing a deep understanding of the relationship between CQDs and electrocatalytic performances,the issues and challenges for the development of CQDs-based composites are discussed.
基金the National Natural Science Foundation of China(No 30570465) the Municipal Science and Technology Committee of Chongqing
文摘Water-soluble CdS quantum dots(CdS-QDs) capped with thioglycohc acid were easily prepared, and a detection method of adriamycin was presented based on the fluorescence quenching of CdS-QDs. It was found that a complex could be formed between cetyhrimethyl ammonium bromide(CTAB) and CdS-QDs by using electrostatic interaction in Britton-Robinson(BR) buffer at pH = 7.00, and the strong fluorescence emission of the complex was observed at 500 nm when the complex was excited at 378 run. The presence of adriamycin, however, could strongly quench the fluorescence through hydrophobic interaction. The overall quenching percentage as a function of adriamycin concentration matches the Stern-Volmer equation very well. These properties make CdS-QDs a potential fluorescence probe for the detection of adriamycin. The detection hmit(3σ) of adriamycin is approximately 10^-9 mol/L.
基金DBT(Grant No.BT/235/NE/TBP/2011 Dated April 30,2012),India,for financial support
文摘Safe, sustainable, and green production of hydro gen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV,which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium.The overall process was performed in accordance with the principles of green chemistry using bio-based precursorsand aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.