【作者】 李阳；

【导师】 宋溪明；

【作者基本信息】 辽宁大学 ， 无机化学， 2014， 硕士

【摘要】 氧化石墨烯是由二维单层平面sp2杂化碳原子组成并具有卓越的光、电、磁等性能的新型碳材料。与石墨烯不同的是由于其表面具有丰富的含氧活性基团,不仅使它的带隙可调,而且具有良好的可修饰性。通过共价和非共价的方式在氧化石墨烯表面引入不同种类的功能分子和基团,使其具有各种特定功能而在更广泛的领域中得到应用,目前已成为科学界研究的热点课题之一。本文利用分子间π-π和静电吸附作用将四种阳离子型金属酞菁分别修饰到石墨烯片层表面,制备了四种阳离子酞菁/石墨烯纳米复合物,对这些复合物结构进行了详细表征,并考察了它们的光电转换性能和催化性能。通过将咪唑阳离子取代基引入到邻苯二腈上得到了阳离子型的酞菁前体化合物,然后通过环合反应制备得到了四种含有四个咪唑阳离子的水溶性锌酞菁(ZnPc)、铜酞菁(CuPc)、镍酞菁(NiPc)、钴酞菁(CoPc)。其中,镍酞菁未见报道。酞菁化合物的结构均通过了核磁氢谱、质谱、红外、紫外-可见吸收光谱的表征,并利用循环伏安法考察了其电化学性能。四种金属酞菁在水中和甲醇中都呈现出良好的溶解性,在甲醇中以单体形式存在。利用分子间π-π和静电吸附作用,分别将制备得到的四种阳离子型酞菁化合物固载到氧化石墨烯片层表面得到了四种新型酞菁修饰的石墨烯纳米复合物,分别为ZnPc-GO、CuPc-GO、NiPc-GO和CoPc-GO,利用红外光谱、紫外-可见吸收光谱、X-射线粉末衍射(XRD)、TEM、XPS等方法对复合物的结构进行了详细表征,四种复合物均未见文献报道。紫外-可见吸收光谱显示酞菁化合物的Q带吸收在吸附前后发生显著的红移,说明酞菁与氧化石墨烯片间存在较强的π-π相互作用。另外,随着浓度的增大,四种复合物在最大吸收波长处的吸收强度符合朗伯-比尔定律,证实四种复合材料在水中均具有很好的分散性。分别以复合物ZnPc-GO、CuPc-GO、NiPc-GO及纯GO作为电极材料,Pt为对电极组装成电池,考察其光电转换性能。结果显示,可见光照射条件下,单纯氧化石墨烯作为电极只有微弱的光电流产生,而以复合物为电极材料时可以检测显著的光电流信号,约是单纯GO的6～40倍,且电流具有良好的稳定性。由此说明该四种酞菁/GO均具有较好的光电转换性能,可以作为光电转换材料用于染料敏化太阳能电池中。最后,考察了可见光照射下复合物CoPc-GO和NiPc-GO催化降解RhB的活性。结果显示,无催化剂存在下,RhB不发生降解;当加入CoPc作为催化剂时,3h后降解率为15%;而分别以复合物CoPc-GO和NiPc-GO为催化剂时,在最佳条件下,即催化剂量为0.6g/L,pH值为6.9时,光照3h后,RhB的降解率分别为92%和91%。且复合物在重复利用3次后,催化性能仅略有下降。更多还原

【Abstract】 Graphene is an outstanding material,consisting of a two dimensional(2D)single layer of sp2-hybridized carbon atoms and possesses excellent electronic and optical properties.Its thin plane geometry,unusual band structure and high carrier mobility make it an ideal material for applications in future optoelectronic devices.It is easy to be modified through introducing different kinds of functional molecules onto its surface by covalent or non-covalent method.Functionalized GO can be applied in many fields.In this work,four novel cationic metallophthalocyanines modified GO nanocomposites through non-covalent method were synthesized and characterized.The optoelectronic transformation properties and photocatalytic properties of these nanocomposites were investigated respectively.Four cationic phthalocyanine ZnPc,CuPc,CoPc and NiPc were synthesized through introducing four imidazole cationic substituents to the phthalocyanine ring firstly.The structure of these complexes were characterized by 1H-NMR,MS,UV-vis spectrum,IR spectrum and element analysis.Their electrochemical properties were studied by cyclic voltammetry method.In addition,these complexes all showed excellent solubilities in water and methanol.Four new composites ZnPc-GO,CuPc-GO,NiPc-GO and CoPc-GO were synthesized through utilizing the π-π interaction between the Pc molecules and the graphene oxide sheet.The structure of the Pc-GO hybrids were characterized by IR spectrum,UV-Vis spectrum,XRD,TEM and XPS methods.A red-shifted and broadened Q-band of these phthalocyanines were found after being adsorbed on the surface of graphene oxide in the UV-Vis absorption spectra of these composites.Therefore,we can speculate there are π-π interaction between the Pc molecule and GO.These Pc-GO hybrids showed good dispersion in water.All these hybrids have not been reported.The photoelectric conversion properties of the composites ZnPc-GO,CuPc-GO,NiPc-GO and pure GO as electrode materials were investigated respectively in a solar cell.The Pc-GO film on FTO substrate gave a obviously reversible rise/decay of the photocurrent in response to the on/off illumination step and the photocurrent intensity are 6～40 times higher than the pure GO film.Therefore,the hybrids ZnPc-GO and CuPc-GO and NiPc-GO have potential applications as a photoelectric conversion material in dye sensitized solar cell.At last,the photocatalytic activities of composites CoPc-GO and NiPc-GO for degradation of RhB under visible light irradiation were studied.Under the optimized experimental conditions with the catalyst concentration=0.6 g/L and pH=6.9,the degradation of RhB rate were 92%and 91%when using CoPc-GO and NiPc-GO hybrids as catalyst respectively after 3h irradiation.In addition,the catalyst can be recycled for 3 times with a little decrease in activity.更多还原