This work is devoted to a novel efficient strategy for single-walled carbon nanotube doping employing heat treatment with nitrogen dioxide (NO). Unlike numerous reports of unstable NO doping at room temperature, our method combines high efficiency and stability, enabled by its temperature-dependent adsorption on the nanotube surface. We reveal that doping stability increases with the treatment temperature reaching maxima at 300 °C avoiding any detrimental effect on nanotube structure and optical transmittance. As a result, we demonstrate doped carbon nanotube transparent conductive films exhibiting competitive performance (in respect to films treated with other dopants) with a less than 50% drop in conductive characteristics for over a year. Thermo-programmed desorption analysis and X-ray photoelectron spectroscopy confirm the preferential formation of long-living adsorbed nitrogen species, such as NO-groups, as a result of high-temperature treatment. We believe the current work provides a basis for the robust and technologically efficient doping of single-walled carbon nanotubes and related structures at industrial scales, as the developed method could be easily coupled with a continuous technology of carbon nano materials production.

中文翻译：

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二氧化氮的高温吸附实现碳纳米管的稳定、高效和可扩展的掺杂

这项工作致力于采用二氧化氮（NO）热处理的单壁碳纳米管掺杂的新颖有效策略。与室温下不稳定的 NO 掺杂的众多报道不同，我们的方法结合了高效率和稳定性，这是通过其在纳米管表面上的温度依赖性吸附实现的。我们发现，随着处理温度在 300 °C 达到最大值，掺杂稳定性会增加，从而避免对纳米管结构和光学透射率产生任何不利影响。结果，我们证明了掺杂碳纳米管透明导电薄膜表现出具有竞争力的性能（相对于用其他掺杂剂处理的薄膜），一年多以来导电特性下降小于 50%。热程序解吸分析和 X 射线光电子能谱证实，高温处理会优先形成长寿命吸附氮物种，例如 NO 基团。我们相信，目前的工作为工业规模的单壁碳纳米管及相关结构的稳健且技术高效的掺杂奠定了基础，因为所开发的方法可以轻松地与碳纳米材料生产的连续技术相结合。