【作者】 曾斌；

【导师】 陈小华；

【作者基本信息】 湖南大学 ， 材料科学与工程， 2013， 博士

【摘要】 随着工业的迅速发展，环境污染问题日趋严重，由于半导体材料可广泛应用于有机污染物的处理，如今越来越受到人们的关注，但是由于其较低的可见光利用率及光催化过程中迅速的光生电子-空穴复合限制了它的应用。在此背景下，本论文充分利用纳米碳材料的高比表面积及优良的导电性能，构建了多种纳米碳半导体复合体系，并系统探索了催化材料的合成及其催化性能。主要展开以下几方面的研究。（1）通过湿化学方法并借助微波辅助加热，制备了石墨烯负载有序介孔硫化锌棒复合物。扫描研究结果表明硫化锌棒直径50nm，长度几百nm左右，且均匀地分布在石墨烯的表面，进一步的透射研究结果发现硫化锌为有序介孔结构。荧光发射谱和光电子能谱证实硫化锌和石墨烯之间形成了紧密的接触。讨论了微波加热功率、微波加热时间以及氧化石墨烯含量对复合物形貌的影响，催化结果表明这种复合材料充分利用了石墨烯优良的导电性和有序介孔结构高的比表面积，能够有效地分解水中的有机污染物。（2）以石墨烯为载体，硫化锌/硫化铜异质纳米颗粒为负载物，制备了具有可见光响应效应的光催化剂。扫描、透射和高分辨研究结果表明硫化锌/硫化铜异质结颗粒均匀分布在石墨烯表面。光催化反应前后的光电子能谱分析证实催化过程中存在电子由硫化锌到硫化铜转移的现象。研究了微波加热功率、微波加热时间、氧化石墨烯含量对复合物形貌的影响。可见光催化结果表明，这种催化剂通过异质纳米颗粒内部的界面电子转移现象，实现了对可见光的有效利用。（3）通过静电自组装并利用微波加热制备了碳纳米管/石墨烯嵌入的氧化亚铜复合球。扫描和透射研究结果表明：碳纳米管/石墨烯嵌入氧化亚铜基体内部，形成了三维的网络结构，与基体共同组成复合球。分别分析了碳纳米管和氧化石墨烯在复合球成形过程中的作用，提出了复合球的形成机理。探讨了微波加热功率、碳纳米管和氧化石墨烯含量以及它们之间的质量比对复合球形貌的影响，光催化实验结果表明纳米碳材料的嵌入，克服了光生电子迁移过程中电子与空穴容易复合的问题，提高了光催化效率。（4）利用喷雾干燥技术制备了碳纳米管/氧化石墨烯/铜盐的球形粉末，并通过煅烧工艺得到碳纳米管/石墨烯球负载氧化铜/氧化亚铜颗粒的复合物。扫描和透射研究结果证明形成碳纳米管/石墨烯球，并在球表面均匀分布大量的纳米颗粒，给出了这种结构的成形过程示意图。探讨了低温煅烧温度、碳纳米管与氧化石墨烯的含量以及它们之间的质量比对复合物形貌的影响，光催化实验结果表明制备的碳纳米管/石墨烯球复合纳米催化颗粒，可进一步提高铜的氧化物的光催化效果，同时还简化了生产工艺，提高了生产效率。更多还原

【Abstract】 With the rapid development of industry, the environmental pollution has becomemore and more serious. As semiconductors can be used to treat organic pollutants,they have attracted considerable attention. However, it has still not been applied inpractice due to its low visible light utilization rate and higher recombination rate ofphotoinduced electron-hole pairs. Under this background, we aim to develop nanocarbon/semiconductor materials based on carbon with excellent electronicconductivity and high specific areas. The synthesized strategy and their photocatalyticperformance were also analyzed. It mainly focusses on the following aspects:(1) Ordered mesoporous ZnS rods decorated graphene nanocomposites weresuccessfully synthesized by wet chemical method with the assistance of microwave.Scanning electron microscopy and transmission electron microscopy confirmed thatthe as-formed ordered mesoporous ZnS rods, about50nm in diameter and severalhundreds of nanometers in length, were distributed on graphene sheets. Fluorescentemission spectra and X-ray photoelectron spectroscopy confirmed that ZnS andgraphene intimately contact with each other. The effects of reaction temperature,reaction time and mass content of graphene oxides on the microstructure andphotocatalytic activity were investigated. The experimental results indicated that thisnanocomposites can decompose MO effectively and it is ascribed to the combinationof excellent conductivity of graphene and high specific area of mesoporous ZnS.(2) The nanocomposites of reduced graphene oxides (rGO) loaded-ZnS/CuSheteronanostructures had been successfully prepared. Scanning electron microscopyand transmission electron microscopy confirmed that ZnS/CuS heteronanostructureswere decorated on the surface of rGO. X-ray photoelectron spectroscopies of thesamples before and after photocatalytic reaction confirmed visible light irradiationinduced interfacial charge transfer from the valence band (VB) of ZnS to CuS clusters.The effects of reaction temperature, reaction time and mass content of graphene onthe microstructure and photocatalytic activity were investigated. The experimentalresults reveal that the high visible light photocatalytic activity is realized due to thephotoinduced interfacial charge transfer inside the heteronanostructures.(3) Carbon nanotubes/reduced graphene oxides (CNTs/rGO) implanting cuprousoxide (Cu2O) composite spheres had been successfully prepared via an electrostatic self-assemble with microwave-assistance. Scanning electron microscopy andtransmission electron microscopy observations confirmed that the hybrid of CNTs andrGO were implanted into Cu2O matrix and formed a three-dimensional embeddedmicrometer sphere structure. The contribution of CNTs, GO to the formation ofspheres was analyzed and the possible formation mechanism of this architecture werealso proposed. The effects of reaction temperature, proportion of carbonnanotubes/graphene oxides and mass content of carbon nanotubes/graphene on themicrostructure and photocatalytic activity were investigated. The experimental resultsindicated that the high visible photocatalytic performances were attributed to carbonmaterials implanted structure.(4) CNTs/rGO sphere decorated with CuxO nanoparticles composite wassuccessfully synthesized by spray drying and post-calcinating method. Scanningelectron microscopy and transmission electron microscopy confirmed that CNTs/rGOformed a spherical micrometer structure and CuxO (x=1or2)nanoparticles weredecorated on their surface. The effects of decomposition temperature, the proportionof carbon nanotubes/graphene oxides and mass content of carbon nanotubes/grapheneon the microstructure and photocatalytic activity were investigated. The experimentalresults indicated that CNTs/rGO sphere decorated with CuxO nanoparticles enhancedphotocatalytic performance as well as simplified technological process and improvedproduction efficiency更多还原