复合碳纳米管增强纳米Ag2CO3的可见光催化活性和稳定性

在二甲基甲酰胺溶液中, 通过简单的沉淀法制备了纳米Ag₂CO₃和碳纳米管(CNT)的复合物. 用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、扫描电镜(SEM)和紫外-可见(UV-Vis)漫反射光谱(DRS)表征了所制备的Ag₂CO₃/CNT复合物, 通过在可见光下降解甲基橙(MO)检测了样品的光催化活性. 结果表明, 纳米Ag₂CO₃颗粒与CNT结合良好. CNT的含量为1.5% (w)的Ag₂CO₃/1.5% CNT复合物活性最高, 经过60 min 的降解, 甲基橙的降解率达到93%. 与纯相纳米Ag₂CO₃比较, CNT的加入还提高了Ag₂CO₃的稳定性, 经过三次循环降解, Ag₂CO₃/1.5% CNT复合物还能降解81%的甲基橙, 而纳米Ag₂CO₃只能降解59.5%的甲基橙. 其活性和稳定性提高的原因是由于CNT的高导电性, 它不仅促进了电子-空穴对的分离, 还能快速转移产生的光生电子.

Enhanced Visible-Light Photocatalytic Activity and Stability of Nano-Sized Ag2CO3 Combined with Carbon Nanotubes

Nano-sized Ag₂CO₃ and carbon nanotube (CNT) composites were fabricated by a facile chemical precipitation approach in N,N-dimethylformamide (DMF) solvent. The as-prepared Ag₂CO₃/CNT samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and ultra violet-visible (UV-Vis) diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methyl orange (MO) under visible light irradiation. The results showed that the nano-sizedAg₂CO₃ particles and CNTs were well combined. The Ag₂CO₃/CNT composite with CNT content of 1.5%(w) exhibited optimal photocatalytic activity under visible light. Ninetythree percent of the MO was removed by the Ag₂CO₃/CNT composite within 60 min. For the Ag₂CO₃/CNT composites, we found that the incorporation of CNT improved the structural stability of Ag₂CO₃ compared with Ag₂CO₃. After three cycles, 81% of the MO was decomposed by the Ag₂CO₃/CNT composite with CNT content of 1.5% (w), but only 59.5% of the MO could be removed by Ag₂CO₃. The improvements in the activity and stability are attributed to the conductive structure supported by CNTs, which favors electron-hole separation and the removal of photogenerated electrons from the decorated Ag₂CO₃.