Dissertation
Dissertation > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials

Fabrication of Microreactors Modified with Noble Metal/Zno Micro/Nanostructures on the Inner Wall and Their Applications

Author ZhangQuan
Tutor WangHongZhi
School Donghua University
Course Materials Physics and Chemistry
Keywords microreactor zinc oxide micro/nanostructures noble metal
CLC TB383
Type Master's thesis
Year 2013
Downloads 82
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Microreactor which possesses outstanding performances in chemical reaction has been widely used in many research fields, such as chemical engineering, materials science, biology et al. In order to meet the functionalization needs of microreactor, fabricating micro/nanostructures on the inner wall of microreactor has a very important significance. As a kind of semiconductor materials. ZnO not only has excellent photoelectric performance, but also can be easily doped and its morphology can be conveniently controlled too. In addition, the ZnO micro/nanostructures possess good performance on modifying the microreactors. So, fabrication of ZnO micro/nanostructures on the inner wall of microreactor has a great significance for expanding the application field of microreactor. In this paper, we have fabricated different ZnO micro/nanostructures on the inner wall of the capillary-based microreactor through the nanotechnology. By pumping the noble metal sols into the microchannel containing preformed ZnO nanorod arrays, different kinds of noble metal/ZnO nanorod arrays modified microreactors were successfully fabricated. Futher more, a series of application researches have been done through these microreactors.Pt/ZnO nanorod arrays modified microreactor was successfully fabricated simply by pumping a Pt sol into the microchannel containing preformed ZnO nanorod arrays, which was constructed through a wet chemical route. The morphology and structure of Pd/ZnO nanorod arrays were characterized through FE-SEM. EDX, XRD, HR-TEM et al. The results showed that the Pt/ZnO nanorod arrays were uniform and their thicknesses were about2-3μm. The microreactor was used for photodegradation of phenol. It showed that the degradation percentage of phenol by Pt/ZnO-5nanorods modified microreactor was about90%after irradiation for180s. The degradation percentage of phenol was still more than85%when the recycling time increased to110h. The results indicated that the microreactor possessed an excellent photocatalytic performance and had a long working life during the continuous photocatalytic process.Pd/ZnO nanorod arrays modified microreactor was successfully fabricated simply by pumping a Pd sol into the microchannel containing preformed ZnO nanorod arrays, which was constructed through a wet chemical route. The morphology and structure of Pd/ZnO nanorod arrays were characterized through FE-SEM, EDX, XRD, HR-TEM et al. The results showed that the Pd/ZnO nanorod arrays were uniform and their thicknesses were about2-3μm. The microreactor was used for catalysing Heck coupling reaction and the reaction conditions were discussed. It showed that in order to get the best catalytic performance, the inner diameter of the microreactor and the flow rate of the solution were200μm and40μL/h respective. The production yield improved when the reaction time increased, until the yield reached100%. It just cost24min when the yield reached100%by using a Pd/ZnO-3nanorod arrays modified microreactor, while, it would cost more than120min in a flask. Thus, the Pd/ZnO nanorod arrays modified microreactor was a microreactor which had the rapid and high efficient catalytic performance.A series of different ZnO/Zn(OH)F core-shell structures have been fabricated on the inner wall of the capillary-based microreactors through a wet chemical route. The morphology and structure of ZnO/Zn(OH)F core-shell structures were characterized through FE-SEM. EDX, XRD, HR-TEM et al. The results showed that the ZnO/Zn(OH)F core-shell structures were uniform and their thicknesses were about2-30μm. The composition of the ZnO/Zn(OH)F core-shell structures included ZnO and Zn(OH)F. Pd-ZnO/Zn(OH)F core-shell structures modified microreactors were successfully fabricated simply by pumping a Pd sol into the microchannels containing preformed ZnO/Zn(OH)F core-shell structures. The microreactors were used for catalysing Heck coupling reaction and the catalytic performances had compared with the Pd/ZnO nanorod arrays modified microreactor. The results showed that Pd-ZnO/Zn(OH)F (1:1) nanowire arrays modified microreactor had the best production yield. By using this microreactor, it just cost30min when the yield reached100%.

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