Abstract

C/Ce-codoped ZnO nanoparticles immobilized onto multi-walled carbon nanotubes (C/Ce-ZnO@MWCNT) were successfully fabricated via the hydrothermal method for degradation of methylene blue (MB) under visible light irradiation. The prepared C/Ce-ZnO@MWCNT samples were characterized by XRD, XPS, FTIR, FE-SEM, EDX, BET, and diffuse reflectance spectroscopy. The obtained results indicated that the photocatalytic activity of all the MWCNTs-containing samples was higher than those of the bare ZnO and C/Ce-codoped ZnO nanoparticles. Besides, the C/Ce-ZnO@MWCNT composite with 50 wt% MWCNT showed the highest photocatalytic activity with the MB removal efficiency of 96.5% recorded within 90 min under visible light illumination using 1.0 g/L catalyst dosage at pH of 9 and MB concentration of 30 ppm. The degradation mechanism controlled by the charge transfer process in C/Ce-ZnO@MWCNT composite was proposed and discussed in detail. In addition, the long-term-use ability of the photocatalyst was also evaluated through experiments conducted in continuous cycles.

摘要

通过水热法成功制备了固定在多壁碳纳米管上的 C/Ce 共掺杂 ZnO 纳米粒子 (C/Ce-ZnO@MWCNT)，用于在可见光照射下降解亚甲蓝 (MB)。通过XRD、XPS、FTIR、FE-SEM、EDX、BET和漫反射光谱对制备的C/Ce-ZnO@MWCNT样品进行表征。所得结果表明，所有含 MWCNTs 样品的光催化活性均高于裸 ZnO 和 C/Ce 共掺杂 ZnO 纳米颗粒的光催化活性。此外，含有 50 wt% MWCNT 的 C/Ce-ZnO@MWCNT 复合材料显示出最高的光催化活性，在可见光照射下，使用 1.0 g/L 催化剂剂量、pH 9 和 MB 在 90 分钟内记录的 MB 去除效率为 96.5%浓度为 30 ppm。提出并详细讨论了C/Ce-ZnO@MWCNT复合材料中电荷转移过程控制的降解机制。此外，还通过连续循环进行的实验评估了光催化剂的长期使用能力。