Synthesized of palladium nanoparticles supported on functionalized 2Dgeraphene oxide and their application in reduction of organic dyes

In this research, Graphene oxide (GO) was first synthesized from natural graphite flakes by a modified Hummers method [1] and in a typical experiment, the obtainedgraphene oxide and Poly(N-vinyl-2-pyrrolidone) or PVP were added to ethanol solution for preparation of .two- dimensional GO [2,3]. In the other step, the surface of 2D-GO functionalized with 3- Aminopropyltriethoxysilane (APTES). APTES is the most commonly used alkoxysilane linker for surface modification of GO due to its terminal amino groups. In this way, one of the three ethoxy groups (–O–CH2– CH2– CH3), which present in the APTES molecule breaks, then leads to covalent bonding between the APTES groups and the 2D-GO. Aliphatic amines are unstable and easily oxidize by aqueous oxidant such as metal ions solution, therefore Pd ions cannot be immobilized on the modified surface with amine groups. For solving this problem and to obtain the more active sites on the surface, during other step terminal amines group of APTES were reacted with aldehyde group of 3,4,5-Trimethoxybenzaldehyde, which imine bond easily formed and ether functional groups coordinated with Pd ions. Finally Pd NPs synthesized by reduction with NaBH4. The synthesized catalyst have been used for the rapid reduction of 4-nitrophenol (4-NP), methyl orange (MO) and methylene blue (MB) in the presence of NaBH4 and shown high catalytic activity.