碳纳米管掺杂聚丙烯腈/铜室温环化为石墨的拉曼光谱分析及形成机制研究

石墨质碳质材料因具有良好的电学、力学、热学性能而在电子设备，复合材料，电池，传感器中得到广泛应用，但针对生产能耗高，污染大，成本高，不可控等现状是急需解决的核心问题。因此，通过使用较简单和成本低的制造技术在纳米级器件中获得石墨碳结构的方法是一个有吸引力的探索领域。表面等离激元技术因具有环境友好、能耗低等优点而受到广泛关注，利用等离激元技术诱导大分子链状聚合物石墨化就是一种具有广阔前景的制备技术，而Cu作为贱金属具有产量高，价格便宜等优势。基于表面等离激元技术，利用激光辐射粗糙Cu表面上的聚丙烯腈（PAN）+碳纳米管（CNT），而使聚丙烯腈在金属表面被石墨化。通过改变基底刻蚀时间、退火温度、退火时间、激光强度系统地研究了PAN/Cu和PAN+CNT/Cu得到最佳石墨化条件。实验结果表明：以PAN作为探针分子，在2.5 mol·L-1硝酸刻蚀15min的铜基底上，观察到了增强因子为1.39×104的表面增强拉曼散射（SERS）效应。通过使用拉曼激光作为光源，在退火温度为140 ℃时，可以观察到石墨化的PAN分子结构缺陷较少，碳氮三键消失，其I_D/I_G可达1.160 8。CNT进一步用于改变粗糙铜基底的光催化性能，我们使用硝酸改性的多臂碳纳米管（MWCNT）与PAN结合对催化系统进行改进，当掺入2%CNT后，通过表面等离激元PAN可以在40 ℃的条件下实现石墨化，其I_D/I_G达到0.942 1，并且激光的引入大大提高了石墨化位点的可控性，将其归因于激光照射下铜表面产生的热电子对PAN的催化作用，并提出可能存在两种催化和石墨化的机制，一种为热电子通过CNT使PAN石墨化，另一种为热电子通过CNT作用于PAN附近的O₂，通过·O-₂使PAN石墨化。

Raman Spectroscopy Analysis and Formation Mechanism of Carbon Nanotubes Doped Polyacrylonitrile/Copper Cyclized to Graphite at Room Temperature

Graphite carbonaceous materials are widely used in electronic equipment, composite materials, batteries, and sensors because of their good electrical, mechanical and thermal properties. However, the current high energy consumption, high pollution, high cost, and uncontrollable production is the core problem that needs to be solved urgently. Therefore, the method of obtaining graphitic carbon structures in nanoscale devices by using simpler and low-cost manufacturing techniques is an attractive area for exploration. Surface plasmon technology has attracted wide attention because of its environmental friendliness and low energy consumption. Using plasmon technology to induce graphitization of macromolecular chain polymers is a promising preparation technology. As a base metal, Cu has the advantages of high yield and low price. Based on the surface plasmon technology, this paper uses laser radiation to graphitize polyacrylonitrile on the metal surface by irradiating polyacrylonitrile (PAN)+carbon nanotubes (CNT) on the rough Cu surface. PAN/Cu and PAN+CNT/Cu were systematically studied to obtain the best graphitization conditions by changing the substrate etching time, annealing temperature, annealing time, and laser intensity. The experimental results show that with PAN as the probe molecule, the surface-enhanced Raman scattering (SERS) effect was observed on the copper substrate etched by 2.5 mol·L-1 nitric acid for 15 minutes. The enhancement factor is 1.39×104. By using the Raman laser as the light source, when the annealing temperature is 140 ℃, it can be observed that there are fewer defects in the graphitized PAN molecular structure and the disappearance of carbon-nitrogen triple bonds, and the I_D/I_G can reach 1.160 8. The CNT is further used to change the photocatalytic performance of rough copper substrates. We use nitric acid-modified multi-walled carbon nanotubes (MWCNT) combined with PAN to improve the catalytic system. When 2% CNTs are incorporated, PAN can achieve graphitization at 40 ℃ by surface plasmons. The I_D/I_G can reach 0.942 1，and the introduction of laser greatly improves the controllability of graphitization sites. We attribute it to the catalysis of PAN by hot electrons generated on the copper surface under laser irradiation. It is proposed that there may be two mechanisms of catalysis and graphitization. One is that hot electrons graphitize PAN through CNT, the other is that hot electrons act on O₂ near PAN through CNT, and PAN is graphitized through ·O-₂.