CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by U...CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by UV-Vis spectrometer,transmission electronmicroscopy(TEM),energy dispersive X-ray spectroscope(EDX)and photoluminescence(PL) spectroscope.The diameter of CdS/ZnS nanoparticle was obvious larger than that of CdS nanoparticle.The diameter of the nanoparticle was estimated,which was confirmed by the images of TEM.The existence of core-shell structure was established by the result of energy dispersive X-ray analysis.PL studies of the samples showed that the luminescence from CdS was enhanced by the ZnS shell.A possible reason was that the ZnS shell reduced the number of defects on the surface of CdS quantum dots,which were assumed to act as centers for radiation-free recombination.展开更多
The intra- and inter-band relaxation dynamics of CdSe/CdS/ZnS core/shell/shell quantum dots are investigated with the aid of time-resolved nonlinear transmission spectra which are obtained using femtosecond pump-probe...The intra- and inter-band relaxation dynamics of CdSe/CdS/ZnS core/shell/shell quantum dots are investigated with the aid of time-resolved nonlinear transmission spectra which are obtained using femtosecond pump-probe technique. By selectively exciting the core and shell carrier, the dynamics are studied in detail. Carrier relaxation is found faster in the conduction band of the CdS shell （about 130 fs） than that in the conduction band of the CdSe core （about 400 fs）. From the experiments it is distinctly demonstrated the existence of the defect states in the interface between the CdSe core and the CdS shell, indicating that ultrafast spectroscopy might be a suitable tool in studying interface and surface morphology properties in nanosystems.展开更多
A novel chemiluminescence（CL） performance of CdTe/CdS/ZnS quantum dots（QDs） with periodate（KIO_4） was studied.Effects of concentration and pH on the CL system were investigated.Electron spin resonance（ESR） and...A novel chemiluminescence（CL） performance of CdTe/CdS/ZnS quantum dots（QDs） with periodate（KIO_4） was studied.Effects of concentration and pH on the CL system were investigated.Electron spin resonance（ESR） and the effects of radical scavenger analysis were employed for identification of intermediate species.The CL spectra for this system showed only one maximum emission peak centered around 620 nm,which was similar with photoluminescence（PL） spectra of CdTe/CdS/ZnS QDs.The CL of CdTe/CdS/ZnS QDs was induced by direct chemical oxidation and the possible mechanism could be explained by radiative recombination of injected holes and electrons.This investigation not only provided new sight into the optical characteristics of CdTe/CdS/ZnS QDs,but also broadened their potential optical utilizations.展开更多
We prepare CdS/CdSe/ZnS thin films by successive ionic layer adsorption and reaction method. Results show a wider photoresponse range of TiO2 mesopores from the ultraviolet region to the visible light region. Sequenti...We prepare CdS/CdSe/ZnS thin films by successive ionic layer adsorption and reaction method. Results show a wider photoresponse range of TiO2 mesopores from the ultraviolet region to the visible light region. Sequentially assembled CdS/CdSe/ZnS quantum and photocurrent efficiency. A high efficiency of dots exhibit significantly improved light-harvesting ability 1.059354% is obtained.展开更多
Photocatalytic water splitting is an economical and sustainable pathway to use solar energy for large‐scale H2production.We report a highly efficient noble‐metal‐free photocatalyst formed by integrating amorphous N...Photocatalytic water splitting is an economical and sustainable pathway to use solar energy for large‐scale H2production.We report a highly efficient noble‐metal‐free photocatalyst formed by integrating amorphous NiS with a CdS nanorods(NRs)/ZnS heterojunction material for photocatalytic H2production in water under visible light irradiation(?>420nm).The results show that the photocatalytic H2production rate reaches an optimal value of up to574μmol·h–1after the loading of NiS,which is more than38times higher than the catalytic activity of pure CdS NRs.The average apparent quantum yield is^43.2%during5h of irradiation by monochromatic420nm light.The present study demonstrates the advantage of integration strategies to form not only semiconductor heterojunctions but also photocatalyst‐cocatalyst interfaces to enhance the catalytic activity for photocatalytic H2production.展开更多
This work reports on a smartphone-based quantitative POCT system which consists of a paper-based microarray chip,a homemade LEGO dark-box,and a smartphone installed with custom-designed FChip-APP,for on-site quantitat...This work reports on a smartphone-based quantitative POCT system which consists of a paper-based microarray chip,a homemade LEGO dark-box,and a smartphone installed with custom-designed FChip-APP,for on-site quantitation of Fe^(3+),Vitamin 12(VB12),and folic acid(FA).Collection and automatic analysis of fluorescence turn-off response of three kinds of fluorescent nanoprobes which are coated onto filter papers by a smartphone-based device is the principle behind this study.The POCT system exhibits good analytical performance for multiplexed analysis of Fe^(3+),VB_(12)and FA with a wide linear range(Fe^(3+),1.0–14.0μg mL^(-1)(R^(2)=0.983);VB_(12),1.35–40.0μg mL^(-1)(R^(2)=0.991);FA,2.0–26.0μg mL^(-1)(R^(2)=0.994))and low detection limit(Fe^(3+),0.35μg mL^(-1);VB12,0.47μg mL^(-1);FA,0.56μg mL^(-1)).The cost and weight of the whole system are~$220 and~600 g per set,highlighting its cost-eff ectiveness and portability.The simple operation procedures and user-friendly interface of the FChip-APP validate the ease-of-use feature of the reported system.This versatile smartphonebased quantitative POCT system provides a cost-eff ective and easy-of-use method for screening the context-specific causes of anemia and thus its eff ective interventions in the future,especially in resource-limited areas.展开更多
文摘CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by UV-Vis spectrometer,transmission electronmicroscopy(TEM),energy dispersive X-ray spectroscope(EDX)and photoluminescence(PL) spectroscope.The diameter of CdS/ZnS nanoparticle was obvious larger than that of CdS nanoparticle.The diameter of the nanoparticle was estimated,which was confirmed by the images of TEM.The existence of core-shell structure was established by the result of energy dispersive X-ray analysis.PL studies of the samples showed that the luminescence from CdS was enhanced by the ZnS shell.A possible reason was that the ZnS shell reduced the number of defects on the surface of CdS quantum dots,which were assumed to act as centers for radiation-free recombination.
基金This work was supported by the National Natural Science Foundation of China （No.11074003） and the Key Program of Educational Commission of Anhui Province of China （No.KJ2010AI32）. For the help of Prof. J. L. Zhao at Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences in sample preparation is greatly appreciated.
文摘The intra- and inter-band relaxation dynamics of CdSe/CdS/ZnS core/shell/shell quantum dots are investigated with the aid of time-resolved nonlinear transmission spectra which are obtained using femtosecond pump-probe technique. By selectively exciting the core and shell carrier, the dynamics are studied in detail. Carrier relaxation is found faster in the conduction band of the CdS shell （about 130 fs） than that in the conduction band of the CdSe core （about 400 fs）. From the experiments it is distinctly demonstrated the existence of the defect states in the interface between the CdSe core and the CdS shell, indicating that ultrafast spectroscopy might be a suitable tool in studying interface and surface morphology properties in nanosystems.
基金supported by the National Natural Science Foundation of China(Nos.81373373,21435002,21227006)
文摘A novel chemiluminescence（CL） performance of CdTe/CdS/ZnS quantum dots（QDs） with periodate（KIO_4） was studied.Effects of concentration and pH on the CL system were investigated.Electron spin resonance（ESR） and the effects of radical scavenger analysis were employed for identification of intermediate species.The CL spectra for this system showed only one maximum emission peak centered around 620 nm,which was similar with photoluminescence（PL） spectra of CdTe/CdS/ZnS QDs.The CL of CdTe/CdS/ZnS QDs was induced by direct chemical oxidation and the possible mechanism could be explained by radiative recombination of injected holes and electrons.This investigation not only provided new sight into the optical characteristics of CdTe/CdS/ZnS QDs,but also broadened their potential optical utilizations.
基金supported by the University of Science of Ho Chi Munh City and Dongthap University
文摘We prepare CdS/CdSe/ZnS thin films by successive ionic layer adsorption and reaction method. Results show a wider photoresponse range of TiO2 mesopores from the ultraviolet region to the visible light region. Sequentially assembled CdS/CdSe/ZnS quantum and photocurrent efficiency. A high efficiency of dots exhibit significantly improved light-harvesting ability 1.059354% is obtained.
基金supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(51772285,21473170)~~
文摘Photocatalytic water splitting is an economical and sustainable pathway to use solar energy for large‐scale H2production.We report a highly efficient noble‐metal‐free photocatalyst formed by integrating amorphous NiS with a CdS nanorods(NRs)/ZnS heterojunction material for photocatalytic H2production in water under visible light irradiation(?>420nm).The results show that the photocatalytic H2production rate reaches an optimal value of up to574μmol·h–1after the loading of NiS,which is more than38times higher than the catalytic activity of pure CdS NRs.The average apparent quantum yield is^43.2%during5h of irradiation by monochromatic420nm light.The present study demonstrates the advantage of integration strategies to form not only semiconductor heterojunctions but also photocatalyst‐cocatalyst interfaces to enhance the catalytic activity for photocatalytic H2production.
基金The financial support from Science and Technology Project of Guangzhou(201803020026)Guangdong Provincial Key Laboratory of Sensing Technology and Biomedical Instruments(2020B1212060077)Guangdong Natural Science Foundation(S2017A030313076,2020A1515010661)
文摘This work reports on a smartphone-based quantitative POCT system which consists of a paper-based microarray chip,a homemade LEGO dark-box,and a smartphone installed with custom-designed FChip-APP,for on-site quantitation of Fe^(3+),Vitamin 12(VB12),and folic acid(FA).Collection and automatic analysis of fluorescence turn-off response of three kinds of fluorescent nanoprobes which are coated onto filter papers by a smartphone-based device is the principle behind this study.The POCT system exhibits good analytical performance for multiplexed analysis of Fe^(3+),VB_(12)and FA with a wide linear range(Fe^(3+),1.0–14.0μg mL^(-1)(R^(2)=0.983);VB_(12),1.35–40.0μg mL^(-1)(R^(2)=0.991);FA,2.0–26.0μg mL^(-1)(R^(2)=0.994))and low detection limit(Fe^(3+),0.35μg mL^(-1);VB12,0.47μg mL^(-1);FA,0.56μg mL^(-1)).The cost and weight of the whole system are~$220 and~600 g per set,highlighting its cost-eff ectiveness and portability.The simple operation procedures and user-friendly interface of the FChip-APP validate the ease-of-use feature of the reported system.This versatile smartphonebased quantitative POCT system provides a cost-eff ective and easy-of-use method for screening the context-specific causes of anemia and thus its eff ective interventions in the future,especially in resource-limited areas.
