氧化石墨插层复合材料的合成及其表征.doc

氧化石墨插层复合材料的合成及其表征中文氧化石墨是近几年来研究者主要关注的无机层状材料之一，由于其主体石墨层上含有丰富的极性基团及片层面积大和带负电荷等特征，这为以氧化石墨为前驱体组装成膜和插层复合提供了可能，一系列具有磁、电、光、催化及分子识别等特性的氧化石墨复合材料相继被成功制备。 基于氧化石墨特殊的结构特征及其复合材料优越的性能和广阔的应用前景，本论文选择了氧化石墨作为插层主体，MnO2 和 TiO2 作为插层客体，通过插入反应技术制备了 MnO2和TiO2插层氧化石墨复合材料，期待合成的氧化石墨插层复合材料能够协同发挥主客体的优异性能，在超级电容器、催化和吸附等邻域得到应用。研究论文主要包括文献综述和实验研究结果两大部分。第一章综述部分主要论述了氧化石墨插层复合材料的结构特征、合成方法、性质、应用领域以及发展前景，提出了本论文的主要工作和研究目的。实验部分(第二、三章)分别介绍了以氧化石墨为前驱体，MnO2 和 TiO2 分别作为插层剂制备氧化石墨插层复合材料的研究工作。 本工作的主要研究论文内容为：(1) 氧化锰插层氧化石墨复合材料的合成研究。利用Hummers法制备了氧化石墨前驱物，并对前驱物进行了分析表征。将氧化石墨前驱物浸入 0.20 M Mn(NO3)2水溶液中搅拌 5 天，得到了剥离状态的氧化石墨分散液。干燥剥离得到的氧化石墨分散液，制备了层间距为 0.78 nm 的Mn2+ 插层氧化石墨材料，锰的插入量为 1.42 mmol/g。然后将 Mn2+ 插层氧化石墨材料在 H2O2 和 LiOH 的混合溶液中搅拌 6 小时，插入到氧化石墨层间的 Mn2+ 被氧化成 MnO2，形成了层间距为 0.75 nm 的 MnO2 柱撑氧化石墨材料；并考察了 Mn(NO3)2 溶液浓度、氧化剂用量和氧化处理时间对产物组成和结构的影响。(2) 氧化钛插层氧化石墨复合材料的合成研究。以氧化石墨作为前驱体，分别研究了其与钛酸四丁酯和十六烷基三甲基溴化胺的插层反应。研究结果表明，前驱体氧化石墨在纯钛酸四丁酯中搅拌 7 天，插入到氧化石墨层间的钛酸四丁酯分子遇到层间的水分子水解生成钛酸，得到了层间距为 1.25 nm 钛酸柱撑的氧化石墨复合材料。钛酸柱撑氧化石墨复合材料中钛的插入量为 1.04 mmol/g，比表面积为 28 m2/g。另一方面，将前驱体氧化石墨在十六烷基三甲基溴化胺水溶液中搅拌7天，得到了层间距为 1.30 nm 十六烷基三甲基胺插层氧化石墨中间体。然后将十六烷基三甲基胺插层氧化石墨浸入到异丙醇钛和乙醇混合溶液中搅拌，得到的悬浮液置于压力溶弹中 50 C 溶剂热处理 48 h，悬浮液过滤，沉淀于 50 C 干燥 2 天，得到了层间距为 1.08 nm 的钛酸插层氧化石墨。钛酸插层氧化石墨保持了层状结构，钛的插入量为 3.12 mmol/g，比表面积为 46 m2/g。钛酸插层氧化石墨在空气中于 300 C 条件下焙烧 2 小时，制备了二氧化钛柱撑的氧化石墨复合材料。采用 XRD,DSC-TGA,SEM,IR,N2 吸附-脱附实验及元素分析等手段对不同阶段产物进行了分析表征。译文Graphite oxide (GO) is one of the inorganic layered materials which were paid much attention to being researched in recent years. Some polar groups embedded in carbon sheets in GO lamellae makes the sheets have negative charge and a large surface area, which is favorable for assembly and intercalation. A series of graphite oxide intercalated materials with novel magnetism, electricity, optic, catalysis and molecule recognition properties have been fabricated. On the basis of the structure characterization and potential applications of graphite oxide and its composites, graphite oxide was chosen as host layer. Both MnO2 and TiO2 were chosen as guest species. MnO2 or TiO2 intercalated graphite oxide composites were fabricated by an intercalation technology in this paper. The obtained MnO2 or TiO2 intercalated graphite oxide composites are expected to show their unique properties of the synergies of both host layers and guest species and be applied in supercapacitor, catalyst, adsorbent and so on. This paper consists of two sections, review and experiments. The structure, synthesis method, property and application of guest intercalated graphite oxide composites were reviewed and the research purpose was showed in the first section (Chapter 1). The experiments section (Chapter 2, and 3) described the fabrication of MnO2 or TiO2 intercalated GO composite with a layered structure and the effect on the properties of GO intercalated materials by changing the reaction conditions. The main research works were as follow: (1) Research on the synthesis of MnO2-pillared GO composite with a layered structure. The precursor of GO was fabricated by Hummers and Offeman from natural graphite powder and its structure was characterized. When GO was soaked in a Mn(NO3)2 aqueous solution and stirred for 5 days, GO was swelled and finally delaminated. After the delaminated GO colloidal suspension was dried, Mn2+-intercalated GO material was obtained, which had a layered structure with a basal spacing of 0.78 nm and the intercalated amount of manganese was 1.42 mmol/g. The Mn2+-intercalated GO material was then treated in a mixed solution of H2O2 and LiOH for 6 h, and the intercalated Mn2+ ions were oxidized to MnO2. A MnO2-pillared layered GO composite with a basal spacing of 0.75 nm was fabricated. The effect of Mn2+ concentrations, the amount of oxidizer and the oxidized time on the composition and structure of the products were investigated.(2) Research on the synthesis of TiO2-pillared GO composite with a layered structure. The prepared GO as a precursor, the intercalation of tetrabutyl titanate and hexadecyl trimethyl ammonium bromide (C16TMA+Br-) into the interlayer of GO was investigated, respectively. The experimental results show that GO was immersed in pure tetrabutyl titanate and stirred for 7 days, tetrabutyl titanate was intercalated in the interlayer of GO and followed to be hydrolyzed into titanate. A titanate intercalated graphite oxide (TIIGO) was obtained, which had a layered structure with a basal spacing of 1.25 nm as well as a BET surface area of 28 m2/g, and the intercalated amount of titanium was 1.04 mmol/g. On the other hand, when GO was immersed in a aqueous solution of C16TMA+Br- and stirred for 7 days, C16TMA+ ion intercalated GO (C16TMAGO) was obtained. After C16TMAGO was treated in a mixed solution of titanate propoxide and ethanol followed by a solvethermal treatment at 50 C for 48 h, a titanate intercalated graphite oxide (C16TIIGO) was obtained, which maintained a layered structure with a basic spacing of 1.08 nm as well as a BET surface area of 46 m2/g, and the intercalated amount of titanium was 3.12 mmol/g. The titanate intercalated graph