Palladium nanoparticle supported on core-shell FeOx@nitrogen-doped carbon cubes and their photocatalytic activities in selective oxidation of alcohols and Ullmann homocoupling in one reaction system

Abstract

In this article, a FeO_x@nitrogen doped carbon (FeO_x@N–C) core–shell cubic nanostructure has been successfully synthesized by the carbonization of ZIF-8 coated Fe₂O₃ cubes. Finally, FeO_x@N–C was successfully decorated with palladium nanoparticles (Pd NPs) in a facile route by reducing H₂PdCl₄ in the presence of sodium borohydride as a chemical reducing agent. The light absorption in the visible region was enhanced with the immobilization of Pd NPs, which suggested that the supported Pd can generate more hot electrons and holes and improves the utilization efficiency of solar light by adsorbing more visible light photons. The as-synthesized photocatalyst was proven to be highly efficient for two organic reactions like Ullmann homocoupling as well as selective oxidation of alcohols in one reaction system. Also, results revealed that the photogenerated hole and electron play significant roles in the coupled reaction and that they join forces with each other to carry out Ullmann homocoupling of bromobenzene and oxidation of benzyl alcohol. It is worth mentioning that the catalyst was simply collected from the solution by using an external magnetic field and reused in six cycles without significant loss of its activity.