Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP.

Methods: CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized water.

Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious.

Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.

背景：4-硝基苯酚（4-NP）是污水中的一种污染物，对人体健康和环境有害。Cu是对硝基化合物具有催化还原作用的非贵金属，具有制备简单，储量丰富，价格低廉的优点。碳纳米管（CNT）由于其出色的机械稳定性和高表面积而被广泛用于基材。在这项研究中，报告了一种通过控制不同的反应时间来制备CNT-Cu2O的简单方法。制备的纳米复合材料用于催化4-NP。

方法：将碳纳米管和氯化铜溶液放入烧杯中，然后在连续搅拌下加入抗坏血酸和氢氧化钠。反应在60℃下进行了足够长的时间。用乙醇和去离子水洗涤后，将准备好的样品在50°C的真空中干燥48小时。

结果：通过扫描电子显微镜和透射电子显微镜技术对这些复合材料的纳米结构进行了表征，放大200纳米的结果表明，Cu2O分布在CNT的表面上。另外，进行X射线衍射以进一步确认Cu 2 O纳米颗粒的形成。紫外分光光度法的结果表明该化合物对4-NP的催化作用是明显的。

结论：CNTs作为负载Cu2O纳米粒子的巨大模板，可以改善Cu2O的稳定性和循环性能。纳米粒子的形成受温度和适当浓度的影响很大，显示出对4-NP还原反应的极大还原性。