氧化石墨烯负载金属硫化物（CdS，ZnS）的制备及电化学性能研究

【作者】 王俊；

【导师】 朱俊武；

【作者基本信息】 南京理工大学 ， 材料学， 2010， 硕士

【摘要】 金属硫化物纳米材料因其独特的物理化学性质显示出在光学、传感、催化和电学等领域广泛的应用前景。氧化石墨(GO)具有准二维层状结构,层面上含有大量-OH、-COOH、-C=O、环氧基等极性官能团,具有丰富的嵌入化学特性。通过原位生长将氧化石墨与金属硫化物结合形成复合材料,不仅可解决金属硫化物团聚问题,而且由于复合效应,以期获得良好的电化学性能。本文首先以乙二胺为溶剂,采用溶剂热法成功制备了氧化石墨烯负载三臂叉状纳米硫化镉复合物(tetrapods-CdS/GO),并考察了硫源、加水量等反应条件对复合物的形貌影响。研究表明以醋酸镉为镉盐,硫化钠为流源,无水乙二胺为溶剂,120℃时反应12h时能获得形貌比较完整的三臂叉状CdS/GO复合物。在此基础上,考虑到溶剂对复合物微观结构的显著影响,以乙醇、乙二醇、N,N-二甲基甲酰胺(DMF)等作为溶剂制备了不同微结构的氧化石墨烯-纳米硫化镉复合材料(CdS/GO),考察了硫源、分散剂等反应条件影响规律。初步研究了不同微结构CdS纳米晶的生长过程以及氧化石墨作为载体与硫化镉的作用机理。在制备CdS/GO的基础上,以乙醇和DMF为溶剂成功制备了氧化石墨烯负载纳米硫化锌复合物(ZnS/GO),考察了溶剂、分散剂等反应条件对复合物形貌的影响。结果表明以醋酸锌为锌盐,硫化钠为硫源,乙醇为溶剂,并添加乙二胺四乙酸(EDTA)为分散剂,140℃时反应24h时能获得负载均匀的ZnS/GO复合物。通过循环伏安法对制备的产物进行了电化学性能测试。根据循环伏安曲线,复合物CdS/GO及ZnS/GO的电容和循环性能都较单纯的CdS及ZnS大幅提高。负载于GO表面硫化物的粒径及其分散性对复合物的电容影响较大。更多还原

【Abstract】 Owing to unique physical properties, nanostructual metal sulfides have exhibited promising applications in many fields such as optics, sensors, catalysis and electrics. Graphite oxide(GO) is a typical two-dimensional layered nanomaterial with plenty of functional groups (such as hydroxyl, carboxyl, carbonyl, epoxy groups) on its sruface, bestowing it with rich intercalation properties. The combination of GO with metal sulfide nanocrystals may result in improved electrochemical properties.In this work, a composite of GO decorated with tetrapods-CdS nanoparticles (tetrapods-CdS/GO) was firstly fabricated via a solvothermal method using ethylenediamine (en) as the solvent. The effects of reaction parameters (sulfide precursors and the addition of De-ioned water) on the morphology and texture of as-obtained products were considered. It showed that tetrapods-CdS/GO was synthesized solvothermally at 120℃for 12h, by using Cd(CH3COO)2-2H2O and Na2S·9H2O as raw materials, pure en as solvent.Taking into account of the facts that solvent exerts a great influnce on the microsturctue of as-synthesized products. Different solvents, like ethonal、ethylene glycol and DMF, were considered as the compensatory system for preparing GO-CdS nanocomposites. Some reaction parameters, like sulfur sources and dispersant was also discussed. The possible mechanism was discussed.On the basis of above experiments, the GO-zinc sulfide nanocomposites (ZnS/GO) were fabricated in the ethanol and DMF system, with the influence of sulfur source and dispersant into consideration. It showed that the well dispersed ZnS/GO was synthesized solvothermally at 140℃for 24h, by using Zn(CH3COO)2·2H2O and Na2S·9H2O as raw materials, EDTA as surfactant, ethanol as solvent.The electrochemical properties of the samples were studied with cyclic voltammetris (CV). The results indicat that the as-obtained composites (CdS/GO and ZnS/GO) have a superor specific-capacitance as well as electeochemcial stabilities than their individual components (CdS, ZnS, and GO). The dispersibility and microstructrue of metal sulfide on GO play a vital role in their electrochemical activities.更多还原