Artificial photosynthesis has gained increasing interest as a promising solution to the worldwide energy and environmental issues. A crucial requirement for realizing a sustainable system for artificial photosynthesis...Artificial photosynthesis has gained increasing interest as a promising solution to the worldwide energy and environmental issues. A crucial requirement for realizing a sustainable system for artificial photosynthesis is to explore low cost, highly-efficient and stable photoactive materials. Carbon nanodots(CNDs) have attracted considerable attention owing to their low cost, tunable chemistry and unique light-harvesting capability. Previous review articles have highlighted the photocatalytic and photoelectrocatalytic applications of CNDs and CNDs-based composite photocatalysts. However, the control of the separation and transfer processes of photogenerated electron/hole pairs in CNDs has not been reviewed.This review summarizes the recent progress in the design of CNDs as new light-harvesting materials and highlights their applications in photocatalytic hydrogen production, CO2 photoreduction and environmental remediation. Strategies that have been employed to modulate the separation and transfer kinetics of photogenerated charge carriers in CNDs are discussed in detail. The challenges and new directions in this emerging area of research are also proposed.展开更多
Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizin...Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism.Herein,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction.More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and core-states.Thus,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information encryption.This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.展开更多
Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings.Recently reported phosphorescence phenomena in aqueous solution have excited re...Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings.Recently reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots(CNDs)is still a challenging issue.Herein,full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement,and Förster energy resonance transfer is used for further tuning phosphorescence range.The phosphorescence spans across most of the visible spectrum,ranging from 400 to 700 nm.In an aqueous solution,the CNDs exhibits blue,green,and red phosphorescence,lasting for approximately 6,10,and 7 s,respectively.Correspondingly,the phosphorescence quantum yields are 11.85%,8.6%and 3.56%,making them readily discernible to the naked eyes and laying a solid foundation for practical application.Furthermore,phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials,showing distinct superiority for accuracy and complete display and imaging in complex emission background.展开更多
A novel concept and approach to engineering carbon nanodots(CNDs)were explored to overcome the limited light absorption of CNDs in low-energy spectral regions.In this work,we constructed a novel type of supra-CND by t...A novel concept and approach to engineering carbon nanodots(CNDs)were explored to overcome the limited light absorption of CNDs in low-energy spectral regions.In this work,we constructed a novel type of supra-CND by the assembly of surface charge-confined CNDs through possible electrostatic interactions and hydrogen bonding.The resulting supra-CNDs are the first to feature a strong,well-defined absorption band in the visible to near-infrared(NIR)range and to exhibit effective NIR photothermal conversion performance with high photothermal conversion efficiency in excess of 50%.展开更多
An unacceptable increase in antibacterial resistance has arisen due to the abuse of multiple classes of broad-spectrum antibiotics.Therefore,it is significant to develop new antibacterial agents,especially those that ...An unacceptable increase in antibacterial resistance has arisen due to the abuse of multiple classes of broad-spectrum antibiotics.Therefore,it is significant to develop new antibacterial agents,especially those that can accurately identify and kill specific bacteria.Herein,we demonstrate a kind of perilla-derived carbon nanodots(CNDs),integrating intrinsic advantages of luminescence and photodynamic,providing the opportunity to accurately identify and kill specific bacteria.The CNDs have an exotic-doped andπ-conjugated core,vitalizing them near-infrared(NIR)absorption and emission properties with photoluminescence quantum yield of 21.1%;hydrophobic chains onto the surface of the CNDs make them to selectively stain Gram-positive bacteria by insertion into their membranes.Due to the strong absorption in NIR region,reactive oxygen species are in situ generated by the CNDs onto bacterial membranes under 660 nm irradiation,and 99.99%inactivation efficiency against Gram-positive bacteria within 5 min can be achieved.In vivo results demonstrate that the CNDs with photodynamic antibacterial property can eliminate the inflammation of the area affected by methicillin-resistant Staphylococcus aureus(MRSA),and enabling the wound to be cured quickly.展开更多
Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a la...Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’self-exothermic reaction at room temperature.The as-prepared CNDs show fluorescence and phosphorescence property,which are comparable with that synthesized by solvothermal and microwave method.Experimental and computational studies indicate that exotic atom doped sp^(2) hybridized carbon core works as an emissive center,which facilities the intersystem crossing from singlet state to triplet state.The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures.The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.展开更多
Cancer is a serious threat to human health.Survival rates of cancer patients are highly dependent on the early diagnosis and treatment.Carbon nanodots(CDs),a rising star of carbon nanomaterial family,can be developed ...Cancer is a serious threat to human health.Survival rates of cancer patients are highly dependent on the early diagnosis and treatment.Carbon nanodots(CDs),a rising star of carbon nanomaterial family,can be developed as a promising terrace for cell labeling,bioimaging,drug delivery,diagnosis,and therapy by virtue of many superior properties including unique photo-luminescence properties,low toxicity,excellent biocompatibility,and easy functionalization.In this mini review,we present the recent progress in fundamental properties of CDs,and highlight their bioapplications in cancer diagnosis and treatment.展开更多
In this work, we demonstrated the successful construction of metal-free zero- dimensional/two-dimensional carbon nanodot (CND)-hybridized protonatedg=C3N4 (pCN) (CND/pCN) heterojunction photocatalysts b; means o...In this work, we demonstrated the successful construction of metal-free zero- dimensional/two-dimensional carbon nanodot (CND)-hybridized protonatedg=C3N4 (pCN) (CND/pCN) heterojunction photocatalysts b; means of electrostatic attraction. We experimentally found that CNDs with an average diameter of 4.4 nm were uniformly distributed on the surface of pCN using electron microscopy analysis. The CND/pCN-3 sample with a CND content of 3 wt.% showed thehighest catalytic activity in the CO2 photoreduction process under visible and simulated solar light. This process results in the evolution of CH4 and CO. Thetotal amounts of CH4 and CO generated by the CND/pCN-3 photocatalyst after 10 h of visible-light activity were found to be 29.23 and 58.82 molgcatalyst-1, respectively. These values were 3.6 and 2.28 times higher, respectively, than thearn*ounts generated when using pCN alone. The corresponding apparent quantum efficiency (AQE) was calculated to be 0.076%. Furthermore, the CND/pCN-3 sample demonstrated high stability and durability after four consecutive photoreaction cycles, with no significant decrease in the catalytic activity.展开更多
Carbon nanodots(CDs) based fluorescent nanoprobes have recently drawn much attention in chemo-/bio-sensing and bioimaging.However,it is still challenging to integrate the colorimetric and fluorometric dual readouts in...Carbon nanodots(CDs) based fluorescent nanoprobes have recently drawn much attention in chemo-/bio-sensing and bioimaging.However,it is still challenging to integrate the colorimetric and fluorometric dual readouts into a single CD.Herein,novel hybrid CDs(HCDs) are prepared by a simple microwave-assisted reaction of citric acid(CA),branched polyethyleneimine(BPEI) and potassium thiocyanate(KSCN).As-prepared HCDs show extraordinary properties,including excitation-dependent emission,satisfactory fluorescence quantum yield(46.8%),excellent biocompatibility and optical stability.Significantly,the fluorescence intensity at 450 nm exhibits linear correlation over the Fe^(3+)concentration from 1 mmol/L to 150 mmol/L with a detection limit(LOD) of 52 nmol/L.Meanwhile,the solution color changes from colorless to orange,and the absorbance at 460 nm increased linearly with Fe^(3+)concentration ranging from 0.02 mmol/L to 5 mmol/L(LOD:3.4 mmol/L).All the evidence illustrates that the HCDs can be conditioned for specific Fe^(3+)sensing with colorimetric and fluorometric dual readouts,which has also been verified with paper-based microchips.The possible mechanism is attributed to the specific interactions between surface functional groups on the HCDs and Fe^(3+).Additionally,the HCDs are successfully applied in sensing Fe^(3+)in wastewater and living cells,demonstrating its potential applications in future environment monitoring and disease diagnosis.展开更多
We reported an unprecedented chemiluminescence(CL)behavior of polyamine-functionalized carbon dots induced by Fe^(3+)–H_(2)O_(2) Fenton-like system.The firststep CL intensity increased with the increasing of the conc...We reported an unprecedented chemiluminescence(CL)behavior of polyamine-functionalized carbon dots induced by Fe^(3+)–H_(2)O_(2) Fenton-like system.The firststep CL intensity increased with the increasing of the concentration of H_(2)O_(2) and Fe^(3+),when the Fe^(3+)concentration came to 10^(−3) M,the unprecedented two-step CL behavior appeared.The CL intensity of BPEI-CDs induced by Fenton-like system was about 10 times stronger than that of naked CDs.The possible two-step CL mechanism was speculated based on the photoluminescence spectra,CL emission spectra,and the effects of radical scavengers on the CL intensity.Radiative recombination of the injected holes by strong oxidant perferrate formed through Fe^(3+)–H_(2)O_(2) reaction and the;OH generated from successive Fenton reaction with the thermally excited electrons was proposed,which further facilitate full understanding about the optical properties of carbon dots.展开更多
Biomass-based carbon nanodots(CNDs) are becoming promising fluorescent materials due to their superior optical properties and excellent biocompatibility. However, most fluorescent CNDs are prepared under high temperat...Biomass-based carbon nanodots(CNDs) are becoming promising fluorescent materials due to their superior optical properties and excellent biocompatibility. However, most fluorescent CNDs are prepared under high temperatures with artificial chemicals as precursors. In this work, multicolor biomass-based CNDs have been prepared by employing natural biomass as precursors through an ultrasonic-assisted method at room temperature. The multicolor biomass-based CNDs can be prepared within 10 min, and cavitation produced by ultrasound in solution contributes to the polymerization of biomolecules into nanodots. The emission of the CNDs covers from blue to red region, with emission peaks centered at 410 nm, 520 nm and 670 nm, and the corresponding photoluminescence quantum yields of the CNDs are 11%, 12% and28%, respectively. Furthermore, bacterial imaging by using the biomass-based CNDs as fluorescent imaging agent has been demonstrated. This work provides a convenient ultrasonic-assisted way for fabrication multicolor and eco-friendly biomass CNDs, demonstrating their application in bacterial imaging.展开更多
A high-quality hybrid Cs_(0.15)FA_(0.85)PbI_(3) thin film is deposited through doping of carbon nanodots(CNDs)into perovskite precursor solution.The corresponding inverted planar perovskite solar cells(PSCs)of ITO/PTA...A high-quality hybrid Cs_(0.15)FA_(0.85)PbI_(3) thin film is deposited through doping of carbon nanodots(CNDs)into perovskite precursor solution.The corresponding inverted planar perovskite solar cells(PSCs)of ITO/PTAA/Cs_(0.15)FA_(0.85)PbI_(3)/PC_(61)BM/BCP/Ag exhibit an improvement in efficiency from 17.36%to 20.06%,which could be attributed to the passivation of the defects at the crystallized perovskite thin film and enhanced perovskite phase uniformity.The results of electron trap density indicate that the addition of CNDs significantly reduces the defects density at the perovskite thin film and the recombination of charge carriers in transport process is minimized.These results demonstrate that low-cost CNDs are effective additives for passivating defects,further reducing charge carrier recombination and improving device efficiency.展开更多
In the present work we develop an electrochemical assisted method to form nanopores on the surface of highly oriented pyrolytic graphite(HOPG),which was accomplished by a simple electrochemical route and a scalable na...In the present work we develop an electrochemical assisted method to form nanopores on the surface of highly oriented pyrolytic graphite(HOPG),which was accomplished by a simple electrochemical route and a scalable nanomaterial,carbon nanodots,without applying high voltages,high temperatures or toxic reagents.HOPG electrodes are in a solution of N-enrich carbon nanodots in acidic media and the potential scans applied on HOPG lead to the formation of a spatially inhomogeneous porous surface.The diameter of the resulting nanopores can be tuned by controlling the number of electrochemical reduction cycles.The resulting nanoporous surfaces are characterized by atomic force microscopy,Raman spectroscopy,scanning electrochemical microscopy,electrochemical impedance spectroscopy and electrochemistry.These nanoporous HOPG showed high capacitance.Hence the potential of these surfaces to the development of energy storage devices is demonstrated.展开更多
Introducing additives into perovskite layers is an effective method to enhance the power conversion efficiency(PCE)and operation stability of perovskite solar cells(PSCs).Herein,we reported an addition of carbon nanod...Introducing additives into perovskite layers is an effective method to enhance the power conversion efficiency(PCE)and operation stability of perovskite solar cells(PSCs).Herein,we reported an addition of carbon nanodots(CNDs)into the CsPbI_(2) Br photoactive layer to boost performance of the related PSCs.It is found that the trap density can be notably suppressed,and the crystallinity can be enhanced after introducing CNDs with an optimal quantity.The PSC with 1.0 wt%addition of CNDs delivers a notable improved average PCE of 13.77%(the highest PCE:14.69%)from that of 12.14%for the control device without CND addition.Moreover,the CND-added CsPbI 2 Br PSCs exhibit superior stability,i.e.,~86% retention of the initial PCE after 160 h aging in air with the humidity of 20%-30%,to the control device.展开更多
The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionali~ particle size, ionic dissolution, etc. This complexity suggests that generalization of a material's ...The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionali~ particle size, ionic dissolution, etc. This complexity suggests that generalization of a material's toxicity may be inappropriate. Moreover, from a medicinal point of view, toxicity can be used for treatment of malignant cells, such as cancer. In this stud~ highly biocompatible carbon nanodots (gCDs) were synthesized by reacting citric acid and urea in glycerol, which resulted in abundant hydroxyl functional groups on the particle surface. gCDs show excitation-dependent photoluminescence but with bright green to yellow emission. Importantly, a series of toxicity assessments showed that as-synthesized gCDs possessed exceptional biocompatibilities to various biological entities including 18 bacteria species, Petunia axillaris seedlings, and Artemia franciscana nauplii. Furthermore, the particles were shown to have low to no toxic effects on human embryonic kidney (HEK-293), breast (MCF-7), and oral squamous (CAL-27) carcinoma cell lines. Of particular interest, the gCDs displayed antiproliferative activities against ovarian choriocarcinoma cells (JAr/Jeg-3 cell lines), which may be further explored for cancer drug discovery.展开更多
Biomass-derived carbon dots(C-dots)are considered a very important carbon material in metal ion detection of their small environmental impact,simple preparation process,and relatively low cost.A green approach for syn...Biomass-derived carbon dots(C-dots)are considered a very important carbon material in metal ion detection of their small environmental impact,simple preparation process,and relatively low cost.A green approach for synthesizing biomass-derived C-dots from Chenpi using a hydrothermal method without further processing is proposed in the present study.The as-synthesized C-dots show excellent fluorescence properties,superior resistance to UV irradiation photobleaching,and high photostability in salt-containing solutions.The C-dots were used in the form of label-free fluorescent probes for sensitively detecting Hg^(2+)selectively.The outcome relationship behaved linearly and was established based on a given range between 10–300 nM concentration,with a detection limit of 7.0 nM.This green strategy obtains a high C-dot quantum yield of 10.8%and satisfactory results in detecting Hg^(2+)in actual water samples.展开更多
Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-sy...Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-synthesize conjugated polymer.Here,we address this issue through the pioneering employment of metal-free and facile-to-synthesize carbon nanodots(CNDs)as the emitter in functional LEC devices.Circular-shaped(average diameter=4.4 nm)and hydrophilic CNDs,which exhibit narrow cyan photoluminescence(peak=485 nm,full width at half maximum=30 nm)with a high quantum yield of 77%in dilute ethanol solution,were synthesized with a catalyst-free,one-step solvothermal process using low-cost and benign phloroglucinol as the sole starting material.The propensity of the planar CNDs to form emission-quenching aggregates in the solid state was inhibited by the inclusion of a compatible 2,7-bis(diphenylphosphoryl)-9,9’-spirobifluorene host compound,and we demonstrate that such pristine host-guest CND-LECs turn on to a peak luminance of 118 cd·m^(−2)within 5 s during constant current-density driving at 77 mA·cm^(−2).展开更多
Transition metal chalcogenides represent a class of the most promising alternative electrode materials for high-performance lithium-ion batteries (LIBs) owing to their high theoretical capacities. However, they suff...Transition metal chalcogenides represent a class of the most promising alternative electrode materials for high-performance lithium-ion batteries (LIBs) owing to their high theoretical capacities. However, they suffer from large volume expansion, particle agglomeration, and low conductivity during charge/discharge processes, leading to unsatisfactory energy storage performance. In order to address these issues, we rationally designed three-dimensional (3D) hybrid composites consisting of ZnSe nanodots uniformly confined within a N-doped porous carbon network (ZnSe ND@N-PC) obtained via a convenient pyrolysis process. When used as anodes for LIBs, the composites exhibited outstanding electrochemical performance, with a high reversible capacity (1,134 mA.h.g-1 at a current density of 600 mA.g-1 after 500 cycles) and excellent rate capability (696 and 474 mA.h.g-1 at current densities of 6.4 and 12.8 A.g-1, respectively). The significantly improved lithium storage performance can be attributed to the 3D architecture of the hybrid composites, which not only mitigated the internal mechanical stress induced by the volume change and formed a 3D conductive network during cycling, but also provided a large reactive area and reduced the lithium diffusion distance. The strategy reported here may open a new avenue for the design of other multi functional composites towards high-performance energy storage devices.展开更多
The rising CO2 level, population boom and increasing energy demand prompts the need of an efficient and sustainable solution to tackle the global warming issue. Reduction of greenhouse gas(GHG) emission through the ...The rising CO2 level, population boom and increasing energy demand prompts the need of an efficient and sustainable solution to tackle the global warming issue. Reduction of greenhouse gas(GHG) emission through the conversion of detrimental CO2 into methanol is one of the most promising solutions for optimising economic and resource efficiency. The utilisation of the abundant and sustainable sunlight to replace thermal and electric energy for CO2 conversion to valuable chemicals is a highly sustainable process and attracted much research interests. Herein, we summarised the catalytic methods for CO2 conversion to methanol, reviewed the photocatalytic properties and efficient photocatalysts, as well as their performance. Carbon [78TD$IF]quantum dots(CQDs) as a new member of the carbon nanomaterials family have attracted increasing attention owing to their excellent photoluminescence property, light harvesting capability, charge recombination suppression and effective electron transport ability. This paper highlighted the multifaceted roles of CQDs in photocatalytic reactions. To this end, the challenges and future directions of CQDs-based photocatalysts have been outlined.展开更多
Electrocatalysts with high catalytic activity and stability play a key role in promising renewable energy technologies, such as fuel cells and metal-air batteries. Here, we report the synthesis of Fe/Fe203 nanoparticl...Electrocatalysts with high catalytic activity and stability play a key role in promising renewable energy technologies, such as fuel cells and metal-air batteries. Here, we report the synthesis of Fe/Fe203 nanoparticles anchored on Fe-N-doped carbon nanosheets (Fe/Fe2Og@Fe-N-C) using shrimp shell-derived N-doped carbon nanodots as carbon and nitrogen sources in the presence of FeCI3 by a simple pyrolysis approach. Fe/Fe203@Fe-N-C obtained at a pyrolysis temperature of 1,000 ℃ (Fe/Fe2OB@Fe-N-C-1000) possessed a mesoporous structure and high surface area of 747.3 m2-g-1. As an electrocatalyst, Fe/Fe203@Fe-N-C-1000 exhibited bifunctional electrocatalytic activities toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media, com- parable to that of commercial Pt/C for ORR and RuO2 for OER, respectively. The Zn-air battery test demonstrated that Fe/Fe2OB@Fe-N-C-1000 had a superior rechargeable performance and cycling stability as an air cathode material with an open drcuit voltage of 1.47 V (vs. Ag/AgCl) and a power density of 193 mW.cm-2 at a current density of 220 mA-cm-2. These performances were better than other commercial catalysts with an open circuit voltage of 1.36 V and a power density of 173 mW-cm^-2 at a current density of 220 mA.cm-2 (a mixture of commercial Pt/C and RuO2 with a mass ratio of 1:1 was used for the rechargeable Zn-air battery measurements). This work will be helpful to design and develop low-cost and abundant bifunctional oxygen electrocatalysts for future metal-air batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(21703039)。
文摘Artificial photosynthesis has gained increasing interest as a promising solution to the worldwide energy and environmental issues. A crucial requirement for realizing a sustainable system for artificial photosynthesis is to explore low cost, highly-efficient and stable photoactive materials. Carbon nanodots(CNDs) have attracted considerable attention owing to their low cost, tunable chemistry and unique light-harvesting capability. Previous review articles have highlighted the photocatalytic and photoelectrocatalytic applications of CNDs and CNDs-based composite photocatalysts. However, the control of the separation and transfer processes of photogenerated electron/hole pairs in CNDs has not been reviewed.This review summarizes the recent progress in the design of CNDs as new light-harvesting materials and highlights their applications in photocatalytic hydrogen production, CO2 photoreduction and environmental remediation. Strategies that have been employed to modulate the separation and transfer kinetics of photogenerated charge carriers in CNDs are discussed in detail. The challenges and new directions in this emerging area of research are also proposed.
基金the National Natural Science Foundation of China(Nos.U2004168,12074348,11974317,12261141661,and 62204223)the China Postdoctoral Science Foundation(No.2022TQ0307)the Natural Science Foundation of Henan Province(Nos.212300410078 and 222102310664)。
文摘Recently,the chemiluminescence(CL)induced by carbon nanodots(CDs)has intrigued researchers’extensive interests in various applications due to its special light emission principle.However,the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism.Herein,the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp2-hybrid core and sp3-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction.More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs,resulting in the variant CL emission from molecular-,crosslinking-and core-states.Thus,the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent,enabling the applications of the CL CDs in illumination and information encryption.This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.
基金supported by the National Natural Science Foundation of China(Nos.11904326,62075198,12274378,and 12304474)the Natural Science Foundation of Henan province(No.222300420087)+1 种基金the Henan Center for Outstanding Overseas Scientists(No.GZS201903)the Key Research and Promotion Projects in Henan Province(No.232102231033).
文摘Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings.Recently reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots(CNDs)is still a challenging issue.Herein,full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement,and Förster energy resonance transfer is used for further tuning phosphorescence range.The phosphorescence spans across most of the visible spectrum,ranging from 400 to 700 nm.In an aqueous solution,the CNDs exhibits blue,green,and red phosphorescence,lasting for approximately 6,10,and 7 s,respectively.Correspondingly,the phosphorescence quantum yields are 11.85%,8.6%and 3.56%,making them readily discernible to the naked eyes and laying a solid foundation for practical application.Furthermore,phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials,showing distinct superiority for accuracy and complete display and imaging in complex emission background.
基金supported by the National Science Foundation of China(No.11204298,61205025,61274126 and 61306081)the Jilin Province Science and Technology Research Project(No.20140101060JC,20150519003JH and 20130522142JH)the Outstanding Young Scientist Program of CAS.
文摘A novel concept and approach to engineering carbon nanodots(CNDs)were explored to overcome the limited light absorption of CNDs in low-energy spectral regions.In this work,we constructed a novel type of supra-CND by the assembly of surface charge-confined CNDs through possible electrostatic interactions and hydrogen bonding.The resulting supra-CNDs are the first to feature a strong,well-defined absorption band in the visible to near-infrared(NIR)range and to exhibit effective NIR photothermal conversion performance with high photothermal conversion efficiency in excess of 50%.
基金the National Natural Science Foundation of China(Nos.11904326,62075198,U2004168 and 12074348)China Postdoctoral Science Foundation(Nos.2019TQ0287 and 2019M662510).
文摘An unacceptable increase in antibacterial resistance has arisen due to the abuse of multiple classes of broad-spectrum antibiotics.Therefore,it is significant to develop new antibacterial agents,especially those that can accurately identify and kill specific bacteria.Herein,we demonstrate a kind of perilla-derived carbon nanodots(CNDs),integrating intrinsic advantages of luminescence and photodynamic,providing the opportunity to accurately identify and kill specific bacteria.The CNDs have an exotic-doped andπ-conjugated core,vitalizing them near-infrared(NIR)absorption and emission properties with photoluminescence quantum yield of 21.1%;hydrophobic chains onto the surface of the CNDs make them to selectively stain Gram-positive bacteria by insertion into their membranes.Due to the strong absorption in NIR region,reactive oxygen species are in situ generated by the CNDs onto bacterial membranes under 660 nm irradiation,and 99.99%inactivation efficiency against Gram-positive bacteria within 5 min can be achieved.In vivo results demonstrate that the CNDs with photodynamic antibacterial property can eliminate the inflammation of the area affected by methicillin-resistant Staphylococcus aureus(MRSA),and enabling the wound to be cured quickly.
基金This work was supported by the National Natural Science Foundation of China(Nos.11904326,U1804155,and U1604263)China Postdoctoral Science Foundation(Nos.2019TQ0287,and 2019M662510)+1 种基金the Chemical Dynamics Research Center(No.21688102)the Key Technology Team of the Chinese Academy of Sciences(No.GJJSTD20190002).
文摘Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’self-exothermic reaction at room temperature.The as-prepared CNDs show fluorescence and phosphorescence property,which are comparable with that synthesized by solvothermal and microwave method.Experimental and computational studies indicate that exotic atom doped sp^(2) hybridized carbon core works as an emissive center,which facilities the intersystem crossing from singlet state to triplet state.The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures.The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.
基金the National Natural Science Foundation of China(21575084)the Natural Science Foundation of Shanxi Province(201701D121019).
文摘Cancer is a serious threat to human health.Survival rates of cancer patients are highly dependent on the early diagnosis and treatment.Carbon nanodots(CDs),a rising star of carbon nanomaterial family,can be developed as a promising terrace for cell labeling,bioimaging,drug delivery,diagnosis,and therapy by virtue of many superior properties including unique photo-luminescence properties,low toxicity,excellent biocompatibility,and easy functionalization.In this mini review,we present the recent progress in fundamental properties of CDs,and highlight their bioapplications in cancer diagnosis and treatment.
文摘In this work, we demonstrated the successful construction of metal-free zero- dimensional/two-dimensional carbon nanodot (CND)-hybridized protonatedg=C3N4 (pCN) (CND/pCN) heterojunction photocatalysts b; means of electrostatic attraction. We experimentally found that CNDs with an average diameter of 4.4 nm were uniformly distributed on the surface of pCN using electron microscopy analysis. The CND/pCN-3 sample with a CND content of 3 wt.% showed thehighest catalytic activity in the CO2 photoreduction process under visible and simulated solar light. This process results in the evolution of CH4 and CO. Thetotal amounts of CH4 and CO generated by the CND/pCN-3 photocatalyst after 10 h of visible-light activity were found to be 29.23 and 58.82 molgcatalyst-1, respectively. These values were 3.6 and 2.28 times higher, respectively, than thearn*ounts generated when using pCN alone. The corresponding apparent quantum efficiency (AQE) was calculated to be 0.076%. Furthermore, the CND/pCN-3 sample demonstrated high stability and durability after four consecutive photoreaction cycles, with no significant decrease in the catalytic activity.
基金Financial support for this work came from the Project of Henan Provincial Medical Science and Technology Research Plan (No.SBGJ202002086)Guangdong Provincial Key Laboratory of Sensing Technology and Biomedical Instruments (No.2020B1212060077)Natural Science Foundation of China (Nos.81901808,81701752, 81601470)。
文摘Carbon nanodots(CDs) based fluorescent nanoprobes have recently drawn much attention in chemo-/bio-sensing and bioimaging.However,it is still challenging to integrate the colorimetric and fluorometric dual readouts into a single CD.Herein,novel hybrid CDs(HCDs) are prepared by a simple microwave-assisted reaction of citric acid(CA),branched polyethyleneimine(BPEI) and potassium thiocyanate(KSCN).As-prepared HCDs show extraordinary properties,including excitation-dependent emission,satisfactory fluorescence quantum yield(46.8%),excellent biocompatibility and optical stability.Significantly,the fluorescence intensity at 450 nm exhibits linear correlation over the Fe^(3+)concentration from 1 mmol/L to 150 mmol/L with a detection limit(LOD) of 52 nmol/L.Meanwhile,the solution color changes from colorless to orange,and the absorbance at 460 nm increased linearly with Fe^(3+)concentration ranging from 0.02 mmol/L to 5 mmol/L(LOD:3.4 mmol/L).All the evidence illustrates that the HCDs can be conditioned for specific Fe^(3+)sensing with colorimetric and fluorometric dual readouts,which has also been verified with paper-based microchips.The possible mechanism is attributed to the specific interactions between surface functional groups on the HCDs and Fe^(3+).Additionally,the HCDs are successfully applied in sensing Fe^(3+)in wastewater and living cells,demonstrating its potential applications in future environment monitoring and disease diagnosis.
基金the National Key Research and Development Program of China(2016YFA0203102)the Chinese Academy of Sciences(XDB14040100)the National Natural Science Foundation of China(Nos.21677152 and 21177138).
文摘We reported an unprecedented chemiluminescence(CL)behavior of polyamine-functionalized carbon dots induced by Fe^(3+)–H_(2)O_(2) Fenton-like system.The firststep CL intensity increased with the increasing of the concentration of H_(2)O_(2) and Fe^(3+),when the Fe^(3+)concentration came to 10^(−3) M,the unprecedented two-step CL behavior appeared.The CL intensity of BPEI-CDs induced by Fenton-like system was about 10 times stronger than that of naked CDs.The possible two-step CL mechanism was speculated based on the photoluminescence spectra,CL emission spectra,and the effects of radical scavengers on the CL intensity.Radiative recombination of the injected holes by strong oxidant perferrate formed through Fe^(3+)–H_(2)O_(2) reaction and the;OH generated from successive Fenton reaction with the thermally excited electrons was proposed,which further facilitate full understanding about the optical properties of carbon dots.
基金supported by the National Natural Science Foundation of China (Nos.11904326,62075198)China Postdoctoral Science Foundation (Nos.2019TQ0287,2019M662510)。
文摘Biomass-based carbon nanodots(CNDs) are becoming promising fluorescent materials due to their superior optical properties and excellent biocompatibility. However, most fluorescent CNDs are prepared under high temperatures with artificial chemicals as precursors. In this work, multicolor biomass-based CNDs have been prepared by employing natural biomass as precursors through an ultrasonic-assisted method at room temperature. The multicolor biomass-based CNDs can be prepared within 10 min, and cavitation produced by ultrasound in solution contributes to the polymerization of biomolecules into nanodots. The emission of the CNDs covers from blue to red region, with emission peaks centered at 410 nm, 520 nm and 670 nm, and the corresponding photoluminescence quantum yields of the CNDs are 11%, 12% and28%, respectively. Furthermore, bacterial imaging by using the biomass-based CNDs as fluorescent imaging agent has been demonstrated. This work provides a convenient ultrasonic-assisted way for fabrication multicolor and eco-friendly biomass CNDs, demonstrating their application in bacterial imaging.
基金his work was supported by Shenzhen Science and Technology Innovation Committee(No.JCYJ20190809172615277)China Postdoctoral Science Foundation(No.2019TQ0163)This project was financially also supported by Shenzhen Municipal Development and Reform Commission,New Energy Technology Engineering Laboratory(No.SDRC[2016]172).
文摘A high-quality hybrid Cs_(0.15)FA_(0.85)PbI_(3) thin film is deposited through doping of carbon nanodots(CNDs)into perovskite precursor solution.The corresponding inverted planar perovskite solar cells(PSCs)of ITO/PTAA/Cs_(0.15)FA_(0.85)PbI_(3)/PC_(61)BM/BCP/Ag exhibit an improvement in efficiency from 17.36%to 20.06%,which could be attributed to the passivation of the defects at the crystallized perovskite thin film and enhanced perovskite phase uniformity.The results of electron trap density indicate that the addition of CNDs significantly reduces the defects density at the perovskite thin film and the recombination of charge carriers in transport process is minimized.These results demonstrate that low-cost CNDs are effective additives for passivating defects,further reducing charge carrier recombination and improving device efficiency.
基金The authors are grateful for the financial support provided by the Ministerio de Ciencia,Innovación,Universidades of Spain(CTQ2017-84309-C2-1-R,RED2018-102412-T)Comunidad Autónoma de Madrid(TRANSNANOAVANSENS Program)+1 种基金Generalitat Valenciana(APOSTD/2017/010)C.G.-S.also acknowledges the financial support from the Comunidad Autónoma de Madrid,Atracción de Talento Program(2017-T1/BIO-5435).
文摘In the present work we develop an electrochemical assisted method to form nanopores on the surface of highly oriented pyrolytic graphite(HOPG),which was accomplished by a simple electrochemical route and a scalable nanomaterial,carbon nanodots,without applying high voltages,high temperatures or toxic reagents.HOPG electrodes are in a solution of N-enrich carbon nanodots in acidic media and the potential scans applied on HOPG lead to the formation of a spatially inhomogeneous porous surface.The diameter of the resulting nanopores can be tuned by controlling the number of electrochemical reduction cycles.The resulting nanoporous surfaces are characterized by atomic force microscopy,Raman spectroscopy,scanning electrochemical microscopy,electrochemical impedance spectroscopy and electrochemistry.These nanoporous HOPG showed high capacitance.Hence the potential of these surfaces to the development of energy storage devices is demonstrated.
基金The authors greatly appreciate the financial support from the Natural Science Foundation of Gansu(Grant No.20JR10RA611).
文摘Introducing additives into perovskite layers is an effective method to enhance the power conversion efficiency(PCE)and operation stability of perovskite solar cells(PSCs).Herein,we reported an addition of carbon nanodots(CNDs)into the CsPbI_(2) Br photoactive layer to boost performance of the related PSCs.It is found that the trap density can be notably suppressed,and the crystallinity can be enhanced after introducing CNDs with an optimal quantity.The PSC with 1.0 wt%addition of CNDs delivers a notable improved average PCE of 13.77%(the highest PCE:14.69%)from that of 12.14%for the control device without CND addition.Moreover,the CND-added CsPbI 2 Br PSCs exhibit superior stability,i.e.,~86% retention of the initial PCE after 160 h aging in air with the humidity of 20%-30%,to the control device.
文摘The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionali~ particle size, ionic dissolution, etc. This complexity suggests that generalization of a material's toxicity may be inappropriate. Moreover, from a medicinal point of view, toxicity can be used for treatment of malignant cells, such as cancer. In this stud~ highly biocompatible carbon nanodots (gCDs) were synthesized by reacting citric acid and urea in glycerol, which resulted in abundant hydroxyl functional groups on the particle surface. gCDs show excitation-dependent photoluminescence but with bright green to yellow emission. Importantly, a series of toxicity assessments showed that as-synthesized gCDs possessed exceptional biocompatibilities to various biological entities including 18 bacteria species, Petunia axillaris seedlings, and Artemia franciscana nauplii. Furthermore, the particles were shown to have low to no toxic effects on human embryonic kidney (HEK-293), breast (MCF-7), and oral squamous (CAL-27) carcinoma cell lines. Of particular interest, the gCDs displayed antiproliferative activities against ovarian choriocarcinoma cells (JAr/Jeg-3 cell lines), which may be further explored for cancer drug discovery.
基金financially supported by the Development Program of Hunan Province (No.2020SK2128).
文摘Biomass-derived carbon dots(C-dots)are considered a very important carbon material in metal ion detection of their small environmental impact,simple preparation process,and relatively low cost.A green approach for synthesizing biomass-derived C-dots from Chenpi using a hydrothermal method without further processing is proposed in the present study.The as-synthesized C-dots show excellent fluorescence properties,superior resistance to UV irradiation photobleaching,and high photostability in salt-containing solutions.The C-dots were used in the form of label-free fluorescent probes for sensitively detecting Hg^(2+)selectively.The outcome relationship behaved linearly and was established based on a given range between 10–300 nM concentration,with a detection limit of 7.0 nM.This green strategy obtains a high C-dot quantum yield of 10.8%and satisfactory results in detecting Hg^(2+)in actual water samples.
基金support from J.C.Kempes Minnes Stipendiefond(No.SMK-1849.1)the Swedish Energy Agency(Nos.45419-1,46523-1,and 50779-1)+2 种基金the Swedish Research Council(Nos.2017-04380,2017-04862,2018-03937,and 2019-02345)the Swedish Foundation for Strategic Research,Stiftelsen Olle Engkvist Byggmästare(Nos.186-0637 and 193-0578)Bertil&Britt Svenssons stiftelse för belysningsteknik,the Swedish Foundation for International Cooperation in Research and Higher Education via an Initiation Grant for Internationalization(No.2019-8553)。
文摘Light-emitting electrochemical cells(LECs)can be fabricated with cost-efficient printing and coating methods,but a current drawback is that the LEC emitter is commonly either a rare-metal complex or an expensive-to-synthesize conjugated polymer.Here,we address this issue through the pioneering employment of metal-free and facile-to-synthesize carbon nanodots(CNDs)as the emitter in functional LEC devices.Circular-shaped(average diameter=4.4 nm)and hydrophilic CNDs,which exhibit narrow cyan photoluminescence(peak=485 nm,full width at half maximum=30 nm)with a high quantum yield of 77%in dilute ethanol solution,were synthesized with a catalyst-free,one-step solvothermal process using low-cost and benign phloroglucinol as the sole starting material.The propensity of the planar CNDs to form emission-quenching aggregates in the solid state was inhibited by the inclusion of a compatible 2,7-bis(diphenylphosphoryl)-9,9’-spirobifluorene host compound,and we demonstrate that such pristine host-guest CND-LECs turn on to a peak luminance of 118 cd·m^(−2)within 5 s during constant current-density driving at 77 mA·cm^(−2).
文摘Transition metal chalcogenides represent a class of the most promising alternative electrode materials for high-performance lithium-ion batteries (LIBs) owing to their high theoretical capacities. However, they suffer from large volume expansion, particle agglomeration, and low conductivity during charge/discharge processes, leading to unsatisfactory energy storage performance. In order to address these issues, we rationally designed three-dimensional (3D) hybrid composites consisting of ZnSe nanodots uniformly confined within a N-doped porous carbon network (ZnSe ND@N-PC) obtained via a convenient pyrolysis process. When used as anodes for LIBs, the composites exhibited outstanding electrochemical performance, with a high reversible capacity (1,134 mA.h.g-1 at a current density of 600 mA.g-1 after 500 cycles) and excellent rate capability (696 and 474 mA.h.g-1 at current densities of 6.4 and 12.8 A.g-1, respectively). The significantly improved lithium storage performance can be attributed to the 3D architecture of the hybrid composites, which not only mitigated the internal mechanical stress induced by the volume change and formed a 3D conductive network during cycling, but also provided a large reactive area and reduced the lithium diffusion distance. The strategy reported here may open a new avenue for the design of other multi functional composites towards high-performance energy storage devices.
文摘The rising CO2 level, population boom and increasing energy demand prompts the need of an efficient and sustainable solution to tackle the global warming issue. Reduction of greenhouse gas(GHG) emission through the conversion of detrimental CO2 into methanol is one of the most promising solutions for optimising economic and resource efficiency. The utilisation of the abundant and sustainable sunlight to replace thermal and electric energy for CO2 conversion to valuable chemicals is a highly sustainable process and attracted much research interests. Herein, we summarised the catalytic methods for CO2 conversion to methanol, reviewed the photocatalytic properties and efficient photocatalysts, as well as their performance. Carbon [78TD$IF]quantum dots(CQDs) as a new member of the carbon nanomaterials family have attracted increasing attention owing to their excellent photoluminescence property, light harvesting capability, charge recombination suppression and effective electron transport ability. This paper highlighted the multifaceted roles of CQDs in photocatalytic reactions. To this end, the challenges and future directions of CQDs-based photocatalysts have been outlined.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 51372248 and 51432009), the Instrument Developing Project of the Chinese Academy of Sciences (No. yz201421) and the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences, the CAS Pioneer Hundred Talents Program and the Users with Potential Program (No. 2015HSC- UP006, Hefei Science Center, CAS), China.
文摘Electrocatalysts with high catalytic activity and stability play a key role in promising renewable energy technologies, such as fuel cells and metal-air batteries. Here, we report the synthesis of Fe/Fe203 nanoparticles anchored on Fe-N-doped carbon nanosheets (Fe/Fe2Og@Fe-N-C) using shrimp shell-derived N-doped carbon nanodots as carbon and nitrogen sources in the presence of FeCI3 by a simple pyrolysis approach. Fe/Fe203@Fe-N-C obtained at a pyrolysis temperature of 1,000 ℃ (Fe/Fe2OB@Fe-N-C-1000) possessed a mesoporous structure and high surface area of 747.3 m2-g-1. As an electrocatalyst, Fe/Fe203@Fe-N-C-1000 exhibited bifunctional electrocatalytic activities toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media, com- parable to that of commercial Pt/C for ORR and RuO2 for OER, respectively. The Zn-air battery test demonstrated that Fe/Fe2OB@Fe-N-C-1000 had a superior rechargeable performance and cycling stability as an air cathode material with an open drcuit voltage of 1.47 V (vs. Ag/AgCl) and a power density of 193 mW.cm-2 at a current density of 220 mA-cm-2. These performances were better than other commercial catalysts with an open circuit voltage of 1.36 V and a power density of 173 mW-cm^-2 at a current density of 220 mA.cm-2 (a mixture of commercial Pt/C and RuO2 with a mass ratio of 1:1 was used for the rechargeable Zn-air battery measurements). This work will be helpful to design and develop low-cost and abundant bifunctional oxygen electrocatalysts for future metal-air batteries.