Facile synthesis of Ag2O/N-doped helical carbon nanotubes with enhanced visible-light photocatalytic activity

Abstract

Novel Ag₂O/N-doped helical carbon nanotubes (Ag₂O/N–HCNTs) were successfully synthesized via a simple coprecipitation method and were well characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). The photocatalytic activities were evaluated in the degradation of methylene blue (MB) aqueous solution. The results showed that Ag₂O nanoparticles sized 3–10 nm were highly anchored on the surface and inner tubes of the N–HCNTs support, and significantly enhanced the visible-light photocatalytic activity compared to bare Ag₂O. It was attributed to the combined effects, including highly dispersed smaller Ag₂O particles and higher charge separation efficiency. The possible mechanism for the photocatalytic activity of Ag₂O/N–HCNTs was also tentatively proposed. In particular, the rate of degradation of the as-prepared Ag₂O/N–HCNTs was 3.9 times faster than that of using bare Ag₂O nanoparticles under visible light irradiation. Furthermore, the Ag₂O/N–HCNTs could be easily recycled in visible photocatalytic activity. In addition, the Ag₂O/N–HCNTs could also degrade MB dye in different water sources like Changjiang River water and tap water with high efficiency as well as in deionized water and that will greatly promote their application in the area of environmental remediation.