- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Efficient photocatalytic inactivation of Escherichia coli by Mn-CdS/ZnCuInSe/CuInS2 Quantum Dots-Sensitized TiO2 nanowires
摘要： A novel visible light-driven photocatalyst (represented as Mn-CdS/ZCISe/CIS/TiO2) for the passivation of Escherichia coli (E. coli) was prepared with TiO2 nanowires as support and CuInS2 (CIS), ZnCuInSe (ZCISe) quantum dots (QDs), and Mn-doped CdS (Mn-CdS) nanoparticles (NPs) as sensitizers. The use of CIS, ZCISe QDs and Mn-CdS NPs extends the light harvest region to visible light. The photoelectric conversion efficiency was consequently improved with a photocurrent density of 12.5 mA/cm2, about 60 times that of the pure TiO2 nanowires. The germicidal efficiency of the photocatalyst was assess by passivation of E. coli, 96% bacteria in 50 mL 105 colony forming units (CFU)/mL solution were killed within 50 min. Besides the high efficiency, the composite has good stability and satisfactory recycling performance. The antibiotic mechanism was also performed by using photoluminescence and scavenging agent of different active matter, revealing that the photo-generated holes play a major role in the sterilization process.
关键词： Quantum dots,Escherichia coli,TiO2,Photocatalysis
更新于2025-09-23 15:21:01
-
Bright CsPbI <sub/>3</sub> Perovskite Quantum Dot Light-Emitting Diodes with Top-Emitting Structure and a Low Efficiency Roll-Off Realized by Applying Zirconium Acetylacetonate Surface Modification
摘要： Zirconium acetylacetonate used as a co-precursor in the synthesis of CsPbI3 quantum dots (QDs) increased their photoluminescence quantum efficiency to values over 90%. The top-emitting device structure on a Si substrate with high thermal conductivity (to better dissipate Joule heat generated at high current density) was designed to improve the light extraction efficiency making use of a strong microcavity resonance between the bottom and top electrodes. As a result of these improvements, light-emitting diodes (LEDs) utilizing Zr-modified CsPbI3 QDs with an electroluminescence at 686 nm showed external quantum efficiency (EQE) of 13.7% at a current density of 108 mA cm?2, which was combined with low efficiency roll-off (maintaining an EQE of 12.5% at a high current density of 500 mA cm?2) and a high luminance of 14 725 cd m?2, and the stability of the devices being repeatedly lit (cycled on and off at high drive current density) has been greatly enhanced.
关键词： CsPbI3 perovskite quantum dots,top-emitting light-emitting diodes,surface modification,zirconium acetylacetonate,efficiency roll-off
更新于2025-09-23 15:21:01
-
Inkjet Printing Matrix Perovskite Quantum Dot Lighta??Emitting Devices
摘要： Perovskite light emitting devices have been expected to be utilized in the field of displays. In this work, a stable FA0.3Cs0.7PbBr3 perovskite quantum dot ink with optimized octane:dodecane cosolvent is obtained by introducing a trace amount of long-chain ligand of oleylamine (OAm) during the quantum dot purification process. A green electroluminescent matrix device with 120 pixels per inch (PPI) is realized from the ink by using an inkjet printing technique, exhibiting a luminance of 1233 cd m?2, a peak current efficiency of 10.3 cd A?1, and an external quantum efficiency of 2.8%. The results may suggest a possibility of making perovskite quantum dot displays by using the inkjet printing technique.
关键词： perovskite quantum dots,inkjet printing,light-emitting diodes
更新于2025-09-23 15:21:01
-
Surface Engineered Hybrid Corea??Shell Sia??Nanowires for Efficient and Stable Broadband Photodetectors
摘要： Silicon nanostructures have gained intensive interest to develop broadband photodetectors at a large-scale due to their excellent electronic properties. Herein, Si-nanowires (SiNWs) decorated with reduced graphene oxide:carbon quantum dots (rGO:CQDs) nanocomposite (NC), as core–shell heterojunction building blocks for broadband (ultraviolet (UV)–near infrared (NIR)) photodetectors (PDs), are demonstrated. The SiNWs and CQDs are synthesized by wet-chemical etching and facile pyrolysis methods, respectively. Photogenerated carriers are transported through rGO because of its high electron mobility and favorable band alignment with CQDs and Si. Further, to minimize the recombination of photogenerated carriers, and enhance the response in the visible region, plasmon-enhanced AuCQDs are incorporated in the shell matrix. The optimized heterostructure (rGO:AuCQDs/undoped CQDs/SiNWs) is sensitive to a broad wavelength range covering the UV to NIR (360 to 940 nm) region, manifests the excellent responsivity of 16 A W?1 at 360 nm, detectivity (D*) of 2.2 × 1013 Jones, and noise equivalent power as low as 2.8 fW Hz?1/2. The optimized PDs heterostructure demonstrates excellent air-stability after 8 days of illumination without any encapsulation or protective coating. The proposed simple, cost-effective, and Si-process-line compatible fabrication of Si-based PD device structure imposes a great promise for highly efficient and stable advanced futuristic optoelectronic devices.
关键词： core–shell heterostructure,detectivity,responsivity,broadband photodetectors,reduced graphene oxide,carbon quantum dots,Si nanowires
更新于2025-09-23 15:21:01
-
Fluorinated graphene nanoparticles with 1-3 nm electrically active graphene quantum dots
摘要： A new perspective approach to how to create a new and locally nanostructured graphene-based material is reported on. We studied the electric and structural properties for the partially fluorinated graphene (FG) films obtained from a FG-suspension and nanostructured by high-energy Xe ions. Local shock heating in ion tracks is suggested to be the main driving force of the changes. It was found that ion irradiation leads to the formation of locally thermal expanded FG and its cracking into nanosized nanoparticles with embedded small (~1.5-3 nm) graphene quantum dots, which band gap was estimated as 1-1.5 eV, into them. A further developed approach was applied to correction of the functional properties of the printed FG-based crossbar memristors. Dielectric FG films with small quantum dots may offer prospects in graphene-based electronics due to their stability and promising properties.
关键词： memristor,molecular dynamics simulation,nanostructuring,swift ion irradiation,fluorinated graphene,graphene quantum dots
更新于2025-09-23 15:21:01
-
Grafting of CdTe quantum dots on thiol functionalized MCM-41 mesoporous silica for 68Ga radiolabeling: introducing a novel PET agent
摘要： Radiolabeled fluorescent nanocomposite, 68Ga@CdTeQDs@SH-Propyl@MCM-41, was prepared. The prepared material was characterized using X-ray diffraction, thermal analysis, radio-thin layer chromatography, field Emission scanning electron microscopy, transmission electron microscopy and N2 adsorption and desorption measurements. In vivo biodistribution and tumor avidity of the nanoconposite was investigated among the organs of rats bearing fibro sarcoma tumor. The results showed that the mesoporous structure of MCM-41 after functionalization and grafting of quantum dots remains intact and the nanosilica can be labeled with 68Ga radionuclide very fast. The results showed a rapid and high tumor uptake for 68Ga@CdTeQDs@SH-Propyl@MCM-41 which revealed that the tumor uptake is modulated by size and character of the host.
关键词： CdTe Quantum Dots,68Ga-Radiolabeled fluorescent nanocomposite,MCM-41
更新于2025-09-23 15:21:01
-
Zinc oxide quantum dots for textile dyes and real industrial wastewater treatment: Solar photocatalytic activity, photoluminescence properties and recycling process
摘要： Three samples of ZnO quantum dots (ZQDs) were synthesized by a modified sol–gel method at different temperatures for 3 h. The first sample (S1) was prepared at room temperature 27 °C, while second and third samples (S2) and (S3) were prepared by the calcination process at 500 and 900 °C, respectively. A study of XRD and TEM determines the purity, high crystallinity and the presence of elongated shape of the prepared catalysts. On using TEM, DRS and EBT analysis, the crystallite size values, bandgap energy, and active surface area were (7.1 nm, 3.49 eV, and 150.1 m2/g), (9.8 nm, 3.45 eV and 112.2 m2/g) and (13.5 nm, 3.39 eV and 78.94 m2/g) for S1, S2, and S3, respectively. The Photoluminescence properties showed that the fluorescence rate for S1 was doubled the observed one in the S2 sample. The photodegradation results of both methyl orange as an industrial raw material and real industrial wastewater of S1 sample showed the finest activity when compared with the rest samples. It was cleared from the collecting data that the photocatalytic performance decreases with the crystallite size increases The mineralization efficiency of the real industrial wastewater that exposed to sunlight for six months were evaluated according to the allowed COD limit for Egyptian Environmental Law, In addition the recycling process for reusable for ZnO prepared samples for 8 times investigated and evaluated.
关键词： Real industrial wastewater,Zinc oxide quantum dots,Solar photocatalytic activity,Recycling process,Sol-gel method
更新于2025-09-23 15:21:01
-
Hydrothermal synthesis of quantum dots dispersed on conjugated polymer as an efficient electrodes for highly stable hybrid supercapacitors
摘要： Hydrothermal synthesis of graphene quantum dots (GQDs) composited with conjugated polymer were investigated the high specific capacitance and cyclic stability of supercapacitor. The situ chemical polymerization method was employed to synthesize the polypyrrole - graphene quantum dots (PPY-GQDs) composite at different concentrations of GQDs. The size, morphology and structural phase of the PPY- GQDs composites was studied by using Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscope (FESEM), Atomic Force Microscope (AFM) and X-ray diffractometry (XRD) techniques respectively. The optical and electrochemical measurements were carried out by using Ultraviolet-Visible (UV–Vis) Absorption spectroscopy, Photoluminescence Spectroscopy (PL) and electrochemical work station. The cyclic voltammetry (CV) results show enhanced current density and area of CV loop with increasing scan rate and the concentration of GQDs. The Supercapacitor was fabricated by two electrodes owns a high energy density 67.8 Wh/kg and 93 Wh/kg at a power density of 1210 W/kg and 1430 W/kg for PGC1 and PGC3 composites. The highest specific capacitance values 467.32 and 647.54F/g are achieved by PGC1 and PGC3 composite compare to pure PPY. The PPY-GQDs composites achieved excellent cycle stability until the 2000 cycle. Thus, it demonstrates that GQDs is playing a unique and important role in improving the performance of a hybrid supercapacitor device.
关键词： Electrochemical Impedance spectra,Graphene quantum dots,Specific capacitance,Supercapacitors,Polypyrrole
更新于2025-09-23 15:21:01
-
Development of a turn-on graphene quantum dot-based fluorescent probe for sensing of pyrene in water
摘要： Polycyclic aromatic hydrocarbons (PAHs) are potentially harmful pollutants that are emitted into the environment from a range of sources largely due to incomplete combustion. The potential toxicity and carcinogenic effects of these compounds warrants the development of rapid and cost-effective methods for their detection. This work reports on the synthesis and use of graphene quantum dots (GQDs) as rapid fluorescence sensors for detecting PAHs in water. The GQDs were prepared from two sources, i.e. graphene oxide (GO) and citric acid (CA) – denoted GO-GQDs and CA-GQDs, respectively. Structural and optical properties of the GQDs were studied using TEM, Raman, and fluorescence and UV-vis spectroscopy. The GQDs were then applied for detection of pyrene in environmental water samples based on a “turn-off-on” mechanism where ferric ions were used for turn-off and pyrene for turn-on of fluorescence emission. The fluorescence intensity of both GQDs was switched on linearly within the 2–10 × 10?6 mol L?1 range and the limits of detection were found to be 0.325 × 10?6 mol L?1 and 0.242 × 10?6 mol L?1 for GO-GQDs and CA-GQDs, respectively. Finally, the potential application of the sensor for environmental water samples was investigated using lake water and satisfactory recoveries (97–107%) were obtained. The promising results from this work demonstrate the feasibility of pursuing cheaper and greener environmental monitoring techniques.
关键词： Polycyclic aromatic hydrocarbons,Pyrene detection,Graphene quantum dots,Fluorescence sensors,Environmental water samples
更新于2025-09-23 15:21:01
-
Phonon-Driven Energy Relaxation in PbS/CdS and PbSe/CdSe Core/Shell Quantum Dots
摘要： We study the impact of the chemical composition on phonon-mediated exciton relaxation in the core/shell quantum dots (QDs), with 1-nm core made of PbX and the monolayer shell made of CdX, where X=S and Se. For this, time-domain non-adiabatic dynamics (NAMD) based on Density Functional Theory (DFT) and Surface Hopping techniques are applied. Simulations reveal twice faster energy relaxation in PbS/CdS than PbSe/CdSe due to dominant couplings to higher-energy optical phonons in structures with sulfur anions. For both QDs, the long-living intermediate states associated with the core-shell interface govern the dynamics. Therefore, a simple exponential model is not appropriate, and the four-state irreversible kinetic model is suggested instead, predicting 0.9 ps and 0.5 ps relaxation rates in PbSe/CdSe and PbS/CdS QDs, respectively. Thus, 2-nm PdSe/CdSe QDs with a single monolayer shell exhibit the phonon-mediated relaxation time sufficient for carrier multiplications to outpace energy dissipation and benefit the solar conversion efficiency.
关键词： Density Functional Theory,phonon-driven energy relaxation,PbSe/CdSe,PbS/CdS,core/shell quantum dots,Surface Hopping techniques,non-adiabatic dynamics
更新于2025-09-23 15:21:01