One-pot, green and surfactant-less synthesis of polyhedral PdNPs anchored on GO as superior catalyst for reduction of 4-nitrophenol

Abstract

An aqueous-based, green, one-pot, and surfactant-less method to synthesize highly dispersed Pd nanoparticles (PdNPs) on graphene oxide (GO) nanosheets at room temperature was reported. The Pd/GO nanocomposites display an even distribution of highly-dispersed polyhedral PdNPs at high density onto GO sheets. The number density and size of deposited PdNPs are facilely adjusted by controlling the quantity of GO in the growth solution. The Pd/GO nanocomposites demonstrate a superior catalytic activity with apparent rate constant k(app) of 1.057 min(-1) and an excellent stability of up to 15 recycle times toward the reduction of 4-nitrophenol (4-NP) without any loss in efficiency. In addition, different factors including the amount of nanocatalysts, GO, ascorbic acid, and the molar ratio of 4-NP vs. NaBH4 also play crucial roles in manipulating the catalytic activities of the as-synthesized Pd/GO nanocomposites. This facile and green synthetic approach combined with their remarkable catalytic activity and durability highlight the potential of the Pd/GO nanocomposites in removal of recalcitrant organic compounds.