Preparation of the GO/Pd nanocomposite and its application for the degradation of organic dyes in water.

A GO/Pd nanocomposite has been successfully synthesized applying a simple method via immobilizing Pd on the surface of the graphene oxide (GO). The GO/Pd nanocomposite was characterized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, Raman, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The surface morphology of Pd NPs was viewed by TEM, the particles are spherical with an average particle size of 11nm. The catalytic activity of the GO/Pd nanocomposite is excellent for the degradation of organic dyes such as Congo red (CR), methylene blue (MB) and methyl orange (MO) in the presence of NaBH4 in aqueous media at room temperature. For the first time, the degradation of CR, MB and MO was reported using GO/Pd nanocomposite as a heterogeneous catalyst. The excellent catalytic effect for the degradation of dyes was monitored by UV-visible spectroscopy at regular time intervals. When GO/Pd nanocomposite was added into the solution containing dye and NaBH4, the intensity of the strong absorption peak gradually decreased and the whole peak disappeared. It followed the pseudo-first order reaction and time of the reduction reactions is short. In addition, the catalyst can be recovered and reused up to multiple runs without any marked loss in its catalytic activity.