【作者】 张娜；

【导师】 邵海波；

【作者基本信息】 浙江大学 ， 化学， 2013， 硕士

【摘要】 基于电化学技术制备金属氧化物纳米材料具有设备简单便宜,操作条件温和且灵活等优点,受到研究者们极大的关注。本论文以Co3O4、TiO2两种典型的金属氧化物为例,提出了基于电化学技术制备金属氧化物纳米薄膜材料的新方法,并研究了所制备材料的相关电化学性能。本论文所提出的电化学方法制备Co3O4、 TiO2纳米薄膜材料的路径操作条件温和、易控,合成产品重现性好、合成周期短、纯度高,或可用于其他多种金属氧化物纳米材料的制备。本论文主要做了以下研究工作：(1)在KOH电解液中,采用循环伏安技术直接氧化金属钴薄膜制备出了Co3O4纳米薄膜材料。通过FTIR、XRD、SEM(?)TEM表征手段对材料的物理学特征进行分析,证明了该材料是由大量竖立式的Co3O4六边形纳米片组成,纳米片厚度约20-50nm,平均直径约200-500nm。作为H2O2电化学传感器,在溶液中检测不同浓度的H2O2表现出了较高的灵敏度,具备了良好的电催化活性。(2)基于电化学技术的多样性和灵活性,在含氨的电解液中,采用常规脉冲伏安氧化技术直接氧化金属钻薄膜制备出了Co3O4纳米薄膜材料。通过XRD、SEM和TEM表征手段对材料进行了物理学表征,证明了该材料是由垂直竖立的纳米片交联组成,纳米片厚度约20nm,边缘长度约1μm。该交联式CO3O4纳米片薄膜作为电催化析氧电极材料,在KOH溶液中,表现了良好催化活性,将析氧起始电位降低到了0.54V(Vs Ag/AgCl),且达到了较高的交换电流密度。(3)在含H2O2的碱性溶液中,利用H2O2的强氧化性和腐蚀作用,以钛箔为钛源和基体,低温条件下制备出了泡沫状TiO2介孔薄膜材料。通过XRD、SEM、TEM手段对材料的物理结构进行表征,证明了所制备的TiO2薄膜材料为金红石相晶型,呈现出了3D的泡沫状多孔结构,孔径约5-30nm,属于介孔材料。该材料在KOH溶液中,对紫外光具有良好的响应,表现出了优良的光电活性。更多还原

【Abstract】 Electrochemical-based strategies for synthesizing metal oxides nanomaterials due to its advantages of simple and cheap apparatus, easy and flexible operation under mild condition have attracted more extensive attentions. In this thesis, we have taken CO3O4, HO2as examples to develop novel synthetic routes based on electrochemical techniques for preparing advanced metal oxides nanomaterials and characterized the performances of as-made products. The electrochemical-based routes we have developed can be used for synthesizing other metal materials due to their advantages such as mild condition and easy controlled of operation; good reproducibility, short period and high purity of products. The main research work of the thesis is list as follows:(1) Adopt Cycle Voltammograms (CV) technique oxidizing cobalt metallic layer directly in KOH electrolyte to synthesize CO3O4nano-film materials. According to FTIR, XRD, SEM and TEM characterizations, we found that the film products are composed of vertical-standing hexagonal nanosheet arrays. The average thickness and edge length of nanosheets is about20-50nm and200-500nm respectively. The as-made film electrodes as electrochemical sensor exhibit high sensitivity and electro-catalysis activity for different concentration of H2O2in solution.(2) Based on the variety and flexibility of electrochemical techniques, adopt Normal Pulse Voltammetry (NPV) technique oxidizing cobalt metallic layer in alkaline electrolyte containing ammonia to synthesize cross-linked Co3O4nanowalls materials. According to XRD, SEM and TEM characterizations, the as-made cross-linked nanowalls arrays have an edge length of up to1μm with thickness of about20nm. The electrode exhibits low oxidation over potential of about0.54V (vs. Ag/AgCl) for oxygen evolution and high exchange current density in alkaline solution which indicating an enhanced catalytic activity.(3) In alkaline electrolyte containing H2O2, adopt Ti foils as titanium source and substrates to synthesize foam-like TiO2nano-film materials based on strong oxidability and corrodibility of H2O2. According to XRD, SEM and TEM characterizations, we found that as-made TiO2nano-film materials in rutile phase with interlaced pores size5-30nm exhibit3D foam-like mesoporous architecture. The porous film electrodes demonstrate prompt photocurrent response and favorable photocurrent density in KOH electrolyte under UV irradiation.更多还原