Controlled Synthesis And Catalytic Properties Of Copper-Based Nanomaterials

Ullmann coupling reactions have been widely used in industry for nearly a century.However,due to the relatively harsh factors such as high temperature,strong alkali,and long reaction time,the reaction leads to serious environmental pollution and energy consumption.Similarly,Michael addition reactions are used as an important method for growing carbon chains in organic synthesis,especially in drug synthesis.However,the existing catalysts are difficult to recycle and reuse,which limits its wide application.In order to improve the reaction process,many researchers have made significant efforts to improve the catalytic efficiency.Meanwhile,because of their high specific surface area,variable valence,and low cost,copper-based nanomaterials have excellent application prospects in catalytical fields.Therefore,it becomes a research hotspot to prepare copper-based nanomaterials with high activity and high stability as heterogeneous catalysts to catalyze a series of organic reactions.In this paper,a simple and effective hydrothermal method has been demonstrated for the preparation of composition tunable?111?-faceted Cu/Cu₂O nanoparticles.The shape evolution of nanoparticles,from octahedral,tetrahexahedron and finally to star-shaped nanostructure,is achieved by gradually increasing the amount of reducing agent in the reaction.The prepared Cu/Cu₂O nanoparticles can be used for the photocatalysis of the C-N Ullmann coupling reaction in the absence of ligands and solvents,showing high catalytical performance in the reaction of aliphatic amines and cyclic amines with halogenated benzenes and obtaining the target products in a high yield.These Cu/Cu₂O nanoparticles also have an excellent catalytic effect on the aza-Michael addition reaction at room temperature.After recycling 5 times,Cu/Cu₂O nanoparticles still maintain a high catalytically activity.Goals of reduction of energy consumption and environment-friendly chemical process have thus been met.