The Preparation Of The ZnSe Quantum Dots、Carbon Quantum Dots And Their Applications

Quantum dots have been widely applied in biolabeling, solar cell, light-emitting diode, visible light photocatalyst, photoelectric detector etc. with their excellent properties. How toprepare high-quality quantumdots with low cost is significant. Compared with traditional ways, low temperature water phase method is a green route with low cost, high water solubility and biocompatibility though the quantum yields is low. So how to improve the fluorescence intensity is an important task. On the other hand, carbon dots are the milestone of how to prepared green nontoxic quantum dots and the research for it will be the focus in feature. What’s more, the applications of the quantum dots and carbon dots are significant. Based on the above, the main works of this paper as follows:1. Surface Plasmons Photoluminescence Enhancement ZnSe/Au nanocomposites and its Bioimaging Application. Highly photoluminescent ZnSe/Au nanocomposites (average size of 3.5 nm) have been prepared via a simple low-temperature-aqueous synthesis and direct coupling approach. Compare with unmodified sample, the quantum yield of modified sample increase from 9.78% tol8.36%. Due to high photostability and biocompatibility, the as-prepared ZnSe/Au nanocomposites are demonstrated as excellent probes in cellular imaging.2. The preparation, properties of carbon dots and their application. The carbon dots with average size of 6-8nm and quantum yield of 10.5% are prepared via hydrothermal method use sucrose as carbon source. Further, the carbon dots are demonstrated as excellent probes in plant. What’s more, the carbon dots show unique up-converted photoluminescence behaviour, which bring new insight into field of catalysis and photovoltaic.3. The visible light catalytic properties of Carbon quantum dots/ZnO nanoflowers composites. Carbon quantum dots/ZnO nanoflowers composites were prepared via electrospinning-hydrothermal synthesis. Experiments demonstrat that the visible light photocatalytic performance of this composite significantly enhanced from 10% to 90% compared with that of pure ZnO nanoflowers, which could be attributed to the unique up-converted photoluminescence behaviour of the carbon dots and the novel 3-D structure of the ZnO.4. Preparation of Carbon quantum dots/TiO2 nanotubes composites and their visible light catalytic applications. Carbon quantum dots/TiO2 nanotubes composites were prepared by electrospinning-hydrothermal synthesis. The visible light photocatalytic activity of composite photocatalyst enhanced from 30% to 98.5%, which is attributed to the carbon quantum dots with the unique up-converted photoluminescence behaviour and the porous structure of TiO2.5. The photoconductivity properties of transparent Ni doped CuAlO2 films. The Ni doped CuA102 films were prepared by sol-gel on single crystal quartz substrates. Experimental results indicate that the photosensitiveness of the film is 215%, the response time of rise time and the decay time are 75 ms and 50ms respectively in 100 mW/cm2 illumination.6. The photosensitivity of the carbon quantum dots/CuAlO2 films composites. The carbon quantum dots/CuAlO2 films composites are prepared via direct coupling method. Experimental results indicate that the films composites whit a high photosensitiveness of 270%, and the response time of rise time and the decay time are 95 ms and 80ms respectively in 100 mW/cm2 illumination.7. The Photovoltaic Conversion Enhancement of C Quantum Dots/p-type CuAlO2/n-type ZnO Photoelectric Device. The bilayer films composites were prepared via sputtered-sol-gel-hydrothermal-direct coupling method. Compared with the unmodified sample, the photoelectric conversion efficiency of the composites increases to 260% and shows a commendable response time of rise and decay time are 95 ms and 80ms respectively, in 100 mW/cm2 illumination.