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一维ZnO纳米结构的制备及其光化学性质的研究

The Research on Preparation and Photochemical Properties of One-Dimension ZnO Nanostructiire

【作者】 徐志堃

【导师】 汤子康; 赵东旭;

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) , 凝聚态物理, 2012, 博士

【摘要】 随着全球工业化进程的发展,环境污染日益严重,环境保护和可持续发展成为人类必须考虑的首要问题。利用光催化技术处理有机污染物及利用具有自清洁作用的超疏水表面来避免污染引起了各国科研人员的兴趣。作为一种宽禁带半导体,ZnO具有多功能性、环境友好等特点,并且ZnO的一维纳米结构容易制备,形貌丰富,在发光器件、紫外探测器、太阳能电池、光催化和疏水表面等领域都有广泛的应用。但是目前ZnO材料在这些方面的研究还存在一些问题,如在光催化和疏水表面应用中的光化学问题:ZnO在溶液环境中进行光催化反应会发生光腐蚀现象,导致催化效率下降;ZnO基疏水表面受到紫外线照射后会向亲水表面转化,无法在户外长期应用。围绕这些问题,本论文进行了研究,并取得如下结果:(1)ZnO纳米线在空气中对有机染料进行光催化降解,表现出优良的固相光催化性能和重复使用性能。经过多次重复性实验,有机物在60分钟后的残留量仅为20%,光催化效率没有明显减弱。经过研究发现,在不同气体环境中ZnO的光催化活性不同,其中氧气和水在固相光催化过程中起重要作用,能够明显提高光催化效率。(2)在空气中进行固相光催化反应,ZnO纳米线表面没有产生新的缺陷,而在溶液环境中进行光催化反应的ZnO纳米线表面腐蚀严重,表明ZnO在固相光催化反应中几乎没有光腐蚀现象,因此能保持稳定的光催化效率,这说明ZnO适合于固相光催化反应。(3)通过电化学沉积法制备出ZnO/Ni多级纳米复合结构,在不使用有机物修饰的情况下构造出了稳定的超疏水表面,而且在这种多级结构中避免了ZnO材料在经过紫外线照射后会出现的浸润性转换现象。

【Abstract】 Along with the development of global industrialization, environment pollutionbecomes an increasingly serious problem. Decomposing organic pollutants viaphotocatalysis and cleaning dirt by super-hydrophobic surface have attracted muchattention around the world. As a wide band gap semiconductor, ZnO is amultifunctional and environmentally friendly material, one-dimensional (1D) ZnOnanostructures could be fabricated easily and have various morphologies. Because ofall these merits,1D ZnO nanostructures have served as building blocks for applicationin light-emitting devices, photodetectors, solar cells, photocatalysts and hydrophobicsurfaces. But, there are still some drawbacks of ZnO, such as photochemical problemsin practical applications of photocatalysis and hydrophobicity: photocorrosion duringthe photocatalysis process and the photoinduced surface wettability conversion afterultraviolet irradiation. This paper presents the study of the above problems and theresults are outlined as follows:(1) The ZnO nanowire arrays showed good photocatalytic activity and stabilityunder air environment. Only20%organic material remained afterphotodecomposition of60min and photocatalytic efficiency did not decrease muchafter cyclic experiments. The photocatalytic properties were studied under differentgas atmosphere. The oxygen and the water both played important roles in photocatalytic process and could enhance the photodecomposition efficiency.(2) The structural defects and photocorrosion of ZnO were serious afterphotocatalytic process under solution environment. But these phenomena were notobserved after the photodecomposition process under air environment and thephotocatalytic efficiency was stable. ZnO was suitable for the photocatalytic processunder air environment.(3) The ZnO/Ni nanorod arrays were fabricated by electrodeposition method.The super-hydrophobic surface was realized without modification of low surfaceenergy organic material. The ZnO/Ni nanorod arrays avoided photoinducedwettability conversion and exhibited durable super-hydrophobicity under long-termultraviolet irradiation.

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