• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nanotechnology >The rapid growth of 3 mu m long titania nanotubes by anodization of titanium in a neutral electrochemical bath
【24h】

The rapid growth of 3 mu m long titania nanotubes by anodization of titanium in a neutral electrochemical bath

机译：在中性电化学浴中通过阳极氧化使3μm长的二氧化钛纳米管快速生长

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The length of titania nanotubes formed by anodization of 0.1 mm thick titanium foil was found to be a strong function of the pH of the electrolyte. The longest nanotubes were formed by using an electrolyte consisting of 1 M Na2SO4 plus 5 wt% NH4F with pH 7. At this pH, after 30 min of anodization, 3 mu m length nanotubular titania arrays with top diameters of similar to 50 nm and bottom diameters of 100 nm were produced. No acid was added to this electrolyte. The formation of titania nanotubes in neutral pH systems was therefore successful due to the excess NH4F in the electrolyte which increases the chemical dissolution process at the metal/oxide interface. Since the pH of the electrolyte at the top part of the nanotubes is kept very high, the dissolution of the nanotubes at the surface is minimal. However, the amount is adequate to remove the initial barrier layer, forming a rather well-defined nanoporous structure. All anodized foils were weakly crystalline and the transformation to anatase phase was achieved by heat treatment at temperatures from 200 to 500 degrees C for 1 h in air. Annealing at temperatures above 500 degrees C induce rutile phase formation and annealing at higher temperatures accelerates the diffusion of Ti4+ leading to excessive growth and the nanotubular structure diminishes.
机译：发现通过阳极氧化0.1mm厚的钛箔形成的二氧化钛纳米管的长度是电解质pH的强函数。最长的纳米管通过使用由1 M Na2SO4和5 wt％NH4F组成的电解质制成，电解质的pH值为7。在此pH值下，经过30分钟的阳极氧化处理后，形成了3μm长的纳米管二氧化钛阵列，其顶部直径类似于50 nm，底部产生了100nm的直径。没有向该电解质中添加酸。因此，由于电解质中过量的NH4F会增加金属/氧化物界面的化学溶解过程，因此在中性pH系统中成功形成了二氧化钛纳米管。由于纳米管顶部的电解质的pH值保持很高，因此纳米管在表面的溶解很小。然而，该量足以除去初始的阻挡层，从而形成相当明确的纳米孔结构。所有阳极氧化箔均为弱结晶，通过在空气中200至500摄氏度的温度下热处理1小时可实现向锐钛矿相的转变。在高于500摄氏度的温度下退火会导致金红石相的形成，而在更高温度下的退火会加速Ti4 +的扩散，从而导致过度生长，并且纳米管结构会减少。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号