CNT/Ag3PO4 composites with highly enhanced visible light photocatalytic activity and stability

A novel CNT/Ag3PO4 composite was synthesized by a two-step method. The physical and chemical properties of catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), diffuse-reflection spectra (DRS) and photocurrent techniques. The XRD, EDS, TEM and XPS analyses indicated that the heterojunction structure had formed in the composite. The DRS analysis showed that the addition of CNT had promoted the optical absorption of Ag3PO4 in the visible region, which meant that it could absorb and use more light energy to enhance the photocatalytic activity. The photocatalytic performance of the samples was evaluated by photocatalytic oxidation of Rhodamine B (RhB) dye under visible light irradiation. The results showed that CNT/Ag3PO4 exhibited much higher photocatalytic activity than the pure Ag3PO4. It was interesting that CNT/Ag3PO4 (0.1 wt%) exhibited the highest photocatalytic degradation efficiency. Moreover, CNT/Ag3PO4 (0.1 wt%) exhibited a higher photocurrent than that of Ag3PO4, which was for the reason that CNT could lead to good electron transfer between the materials. The mechanism of the CNT/Ag3PO4 composite with enhancing heterojunction photocatalytic activity was researched. (C) 2013 Elsevier B.V. All rights reserved.