Anchoring and stabilization of colloidal PdNPs on exfoliated bis-thiourea modified graphene oxide layers with super catalytic activity in water and PEG

Anchoring and stabilization of colloidal noble metal particles (CNMPs) with good distribution have remained an enormous challenge in catalytic applications. However, designing a catalytic system with complementary properties including high surface area, high loading, extraordinary electronic properties, and easy separation offers a promising route for efficient utilization of layers nanostructures for various applications. Herein, an environmental benign approach was developed to fabricate novel catalysts consist of graphene oxide (GO) functionalized with bis-thiourea (BTU) linker. This methodology helps to stabilize and distribute colloidal palladium nanoparticles (Pd NPs) and increases the surface electron density of nanoparticles by electron-donating from BTU ligand. The catalytic activity of Pd NPs supported on the BTU surface was developed in carbon-carbon coupling reactions and nitroarenes reduction under very mild and sustainable reaction conditions. The outstanding catalytic performance can be ascribed to the stabilization of colloidal Pd with particle size 4.6 +/- 0.8 nm, as well as the unique three-dimensional network structure of BTU-GO, being favorable for rapid mass transferring. Our finding indicates that the proposed catalyst is a greener, recyclable, and more suitable option for the large-scale application and could pave a way for construction of other transition metal-based catalysts for wide applications.