金属镍在碳纳米管薄膜上的电结晶

Electrocrystallization of nickel on carbon nanotubes film

为了使碳纳米管表面产生某些含氧官能团,使其疏水性表面变为亲水性表面,采用兼具有酸性和氧化性的硝酸和硫酸水溶液对碳纳米管进行表面氧化处理,并利用红外光谱表征了碳纳米管的表面结构.制备了初始浓度为0.5g/L的碳纳米管悬浮液,运用复合电沉积方法在不锈钢基体表面制备碳纳米管薄膜,同时在硫酸镍基础电解液中研究了沉积时间对镍晶粒在碳纳米管薄膜上沉积的表面形貌和微观结构的影响.结果表明:经过混酸氧化处理后的碳纳米管表面拥有丰富的羧基和羟基等含氧官能团;沉积初期镍晶粒在碳纳米管薄膜中的结晶形态呈颗粒状,其结晶位置仅位于碳纳米管表面少数部位,随着沉积时间的延长,镍晶粒在碳纳米管薄膜中逐渐形成准连续的金属层.此外,碳纳米管的存在促进了镍晶粒(111)晶面的生长,影响了特征峰相对强度的变化及晶粒尺寸的减小.

To generate some oxygen-containing surface groups at the carbon nanotubes（CNTs） surface, which converts the hydrophobic surface into hydrophilic surface, carbon nanotubes were oxidized by using the mixture of nitric acid （HNO3） and sulfuric acid （HzSO4） with strong acidity and oxidizability, and characterized by using the infrared spectroscopy （IR）. Carbon nanotubesfilm was fabricated from carbon nanotubes suspensions with an initial concentration of 0. 5 g/L by electrodeposition on the stainless steel. The effects of the deposition time on the surface morphology and microstructure of nickel on the CNTs film were investigated by using sulfuric nickel electrolyte. The results show that hydroxylic groups and carboxytic groups generate on the surface of CNTs after the mixed acid treatment. In the early stage of nickel electrodeposition on the CNTs film, nickel is deposited as graininess morphology on some parts of the surface of CNTs. With prolonging the time of deposition, the deposit layer of nickel progressively increases on the CNTs film, leading to a quasi- continuous nickel layer. In addition, the presence of CNTs promotes the growth of the （111） crystal plane of the nickel crystallites, effects the change of the characteristic peak relative intensity and the grain size decrease.